Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
'7991
METHOD FOR CONTROLLING THE POSITION OF THE CUTTING EDGES AT A LONG-
TUDINAL CUTTER MEANS FOR WEBS OF PAPER AND THE LIKE AS WELL AS
CORRESPONDING LONGITUDINAL CUTTER APPARATUS
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The invention relates to a method of the type corresponding to the
preamble of claim 1 and also relates to a corresponding longitudinal
cutter apparatus.
Such a method and such a longitudinal cutter apparatus are known from
the German Letters Patent 21 42 117. The carriages with the circular
knives are thereby shifted by the conveyor means into predetermined
positions which correspond to the desired width of the sub-webs to be
produced from a wide paper roll. As long as the position of the cutting
edges of the circular knives remains invariable relative to the carriage,
this positioning can be arbitrarily repeated and the widths of the sub-
webs can be set with the tolerance given by the working precision of
the conveyor means.
The circular knives, however, must be reground from time to time since
the stress and the wear due to the paper webs passing through with
speeds up to 2500 meters per minute are considerable. This is particularly
true for the driven, so-called ledger [or: bottom] blade which is de-
signed pot-like, whereby the shearing interaction with the flat, so-
called top cutter occurs at the end face of the edge of the pot. During
regrounding, this pot edge is ground off so that the pot becomes "lower".
It can thereby definitely be a matter of amounts of 1 to 2 mm.
When the positioning is restricted to bringing the carriages to a spew
cilia location and the position of the cutting edge relative to the
carriage has changed, this dislocation enters into the width of the
sub-webs produced, these thus deviating from their rated dimension by
corresponding amounts.
This is inadmissible in many instances. It is known to compensate the
change in the position of the cutting edges due to the grinding with
shims. This method wastes time and is subject to error because the
needed shims must be determined by means of measurements to be undertaken
at every pair of blades and errors due to tolerances remain.
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The object of the invention is to create a method and a longitudinal
cutter apparatus wherein a positioning of the cutting edges at the Sue-
cuter knives is possible even after a regrinding thereof in a simpler
fashion without shims and, nonetheless, with greater reliability.
This object is achieved in terms of its methodological aspect by means
of the features recited in the characterizing part of claim 1.
As in the known embodiment, the positioning of the carriages thus ensues
by means of setting the interval between an outer, apparatus-fixed bench
mark and a carriage-fixed bench mark. The position of the cutting edge
changed by the regrinding, however, is acquired by means of a measure-
mint and taken into consideration in the control, so that the carriage
is not placed at a different position such that the position of the
cutting edge again assumes its rated position and the width of the sub-
webs produced is not influenced by the regrinding.
This all ensues by means of a measurement given [a] position of the
cutting edge changed after the regrinding, so that errors as can occur
in the selection of the correct shims and tolerances that may arise no
longer play any part.
The inventive solution of the object in terms of its apparatus-related
aspect is reflected in claim 2.
A simple formation of the carriage-fixed bench mark which is easy to
acquire by means of external measuring devices can, in accord with
claim 3, be given by means of an edge at the carriage which, in accord
with claim I, can be formed by a special measuring piece.
In the embodiment of claim 5, the measuring means comprises outer, stayshunner position sensors past which both the edge of the reground air-
cuter knives as well as the edge at the measuring piece forming the
carriage-fixed bench mark travel and generate pulses when a blade carriage
is displaced. These pulses can be employed for deeming the spacing
[between] the two said edges.
All embodiments known from the Prior Art for this purpose come into con-
side ration as position sensors, for example inductive or magnetic sensors,
micro switches mechanically actuated by the edges, photoelectric and
pneumatic sensors, etc.
After the blades have been built in, the distance of the cutting edge of
the reground (or new) ledge [or: bottom] blade from the edge forming
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the carriage-fixed bench mark is determined at every pair of blade
carriages in an operating cycle preceding the positioning in that the
blade carriages are conducted past the position sensors respectively
intended for them.
The problem thereby arises that the control must be able to unequivocalallocate the pulses arising when passing the cutting edge and the
measuring edge to a specify pair of blade carriages.
The feature of claim 6 serves this purpose. It enables the pulses of the
different pairs of blade carriages to be separated from one another. The
blade carriages are entrained along the rails by the conveyor means. On
the basis of the specified design, the pairs of blade carriages do not
reach the allocated position sensors simultaneously but at specific in-
tervals. In this fashion, the signals of the individual position sensors
can be separated from one another and be allocated respectively to a spew
cilia pair of blade carriages. The signals which appear in a defined
displacement range of the conveyor means can only derive from a defined
pair of blade carriages.
It is most expedient to have the intervals increase by identical amounts
in accord with claim 7.
An exemplary embodiment of the invention is schematically illustrated in
the drawing.
JIG 1 shows a vertical longitudinal section through the essential part
of the apparatus;
FIG 2 shows an elevation according to FIG 1 from above, partially in
section and given omission of the upper deflection drum;
FIG 3 shows a schematic view of the conveyor means;
FIG 4 shows a side view of a single ledger or: bottom] blade carriage;
FIG 5 shows a view according to FIG 4 from the left with an additionally
indicated position sensor;
FIGS 6 and 7 show schematic sectional views of the locking means con-
twined in the blade carriage;
FIG 8 shows a single blade pair emphasized in enlarged scale;
JIGS 9 through 11 show an enlargement of the region in FIG 8 indicated
with dot-dash lines given various regrinding conditions of the
ledger [or: bottom] blade;
FIG 12 is a schematic illustration of the pulses for the control of the
conveyor means.
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the paper web 1 runs butter two deflection drums [or: rollers] 2,3 which
en- seated in the machine frame M, running vertically in the indicated
direction through the apparatus and being longitudinally cut there. The
supply reel and the sub-reels onto which the sub-webs produced by the
longitudinal cuts are rewound are not shown.
The division of the web ensues by means of interacting circular knives,namely the so-called ledger [or: bottom] blade 4 and the top cutter 5.
The ledger [or: bottom] blade 4 is seated at a ledger [or: bottom] blade
carriage referenced 6 overall which is guided at a rail connected to
the machine frame M and extending transversely across the web width.
A conveyor rod 8 is displaceable in longitudinal direction in the rail 7,
the ledger [or: bottom] blade carriage 6 being connectable as desired
to said conveyor rod 8 in order to displace it along the rail 7 into
a desired position which corresponds to the location of the cut in the
web 1. The design of the ledger [or: bottom] blade carriage 6 shall be
explained in greater detail with reference to FIGS 4 through 7.
The ledger [or: bottom] blade 4 is driven in the indicated sense, whereas
the top cutter 5 does not have a drive but is merely loosely entrained.
It is seated at the top cutter carriage referenced overall with 9 which,
just like the ledger [or: bottom] blade carriage 6, is displaceable by
a conveyor rod 10 along a rail 11 secured to the machine frame M which
extends transversely across the web width. A pneumatic piston/cylinder
unit issue disposed on the ledger [or: bottom blade carriage 12, the
piston 13 thereof being extendible perpendicular to the web 1 against
the ledger [or: bottom] blade carriage 6 against the action of a spring
14. Seated at the front end of the piston rod 15 is a further piston/
cylinder unit 16 who's axis extends parallel to the axis of the ledger
[or: bottom] blade 4 and whose piston is displaceable such against the
action of a spring 18 that the top cutter 5 is upwardly entrained act
cording to FIG 2.
The piston cylinder unit 12 serves for the control of the adjustment ofthe top cutter 5 against the ledger [or: bottom] blade 4 [and] the piston/
cylinder unit 16 [serves] for producing the seating of the top cutter 5
against the end edge 19 of the ledger [or: bottom] blade 4 which forms
the cutting edge, whereby a prescribed cutting pressure is observed. The
control ensues by means of a solenoid valve 20 allocated to every top
cutter carriage 9, said solenoid valve, when actuated, allowing come
pressed air from the feed line 21 to proceed via the line 22 behind the
piston 13 of the piston/cylinder unit 12, whereby the top cutter 5 act
coding to PIG 1 is displaced toward the right. When the displacement has
been carried out, the channel 23 formed in the piston 13 and in the
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piston rod 15 comes into communication with the compressed air feed
line 22 and the piston/cylinder unit 16 receives compressed air so that
the top cutter 5 is drawn against the end face 19 of the ledger [or:
bottom] blade 4. The actuation thus ensues in a sequence which prevents
the top cutter 5 from striking against the circumference of the ledger
[or: bottom] blade 4.
The solenoid valve 30 which is allocated to every blade pair 4,5 or,
respectively, to every carriage pair 6,9 serves for the initiation of
the locking or, respectively, unlocking of the carriages 6,9 at the
appertaining rails 7,11. The compressed air is advanced via the line 26.
The locking and unlocking means explained in yet greater detail in con-
junction with FIGS 6 and 7 is of such a nature that it either releases
the carriages 6,9 at the rails 7,11 and simultaneously couples with the
conveyor rod 8,11 [sic] or uncouples therefrom and locks to the rails
7,11. The actuation of the locking and unlocking fixture occurs by means
of the solenoid valve 30 via the lines 27,28 simultaneously at the
carriages 6,9, so that both carriages 6,9 can be simultaneously moved.
Numbers of carriages 6,9 allocated to one another are respectively present
corresponding to the number of longitudinal divisions] of the paper web 1
that are desired. In the schematic illustration of the conveyor means of
FIG 3 which is referenced 40 overall, five pairs of carriages are pro-
voided, whereby the top cutter carriages 9 are merely indicated by means
of the locking and unlocking fixtures 50 and the top cutters 5.
The conveyor rods 8,10 are displaced in longitudinal direction by a motor
operator 41 via worm gearings 42 and ball caster spindles 43. The worm
gearings 42 of both conveyor rods 8,10 are connected to one another via
an articulated shaft 44, so that the conveyor rods 8,10 and, thus, the
carriages 6,9 are always displaced by identical amounts a the rails
7,11 (FIG 1).
A pulse generator 45 which resolves the transport motion of the conveyor
rod 8 into discrete pulses is situated at the worm gearing 42 ox the
conveyor rod 8 for the ledger [or: bottom] blade 4. Every counted pulse
thus corresponds to a specific transport path of the blades.
At the beginning of the positioning, the conveyor rod 8 is pulled back
against a Nero dead stop which represents an apparatus-fixed bench mark.
The carriages 6 are thereby situated in their starting position which
are established by the spacing of index bores 47 in the conveyor rod 8.
The cogs of the locking and unlocking fixtures 50 engage into these
index bores 47, the design of said fixtures still to be explained in
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detail with reference to FIGS 6 and 7. no their starting position,
however, the carriages are uncoupled from the conveyor rod 8 and are
fixed to their rail 7. When, for example, the first carriage from the
loft according to FIG 3 is to be brought into a specific position, then
it is uncoupled from the rail 7 and coupled to the conveyor rod 8 by
means of engagement into the appertaining index bore 47 of the conveyor
rod 8. The motor operator 41 is then actuated until, proceeding from
the seating against the zero dead stop 46, a specific plurality of pulses
of the pulse generator 45 has been traversed and the conveyor rod 8 has
covered a corresponding distance. The carriage 6 has then reached its
desired position and is uncoupled from the conveyor rod 8 and coupled
to the rail 7. This procedure is executed such for all carriages 6 that
the conveyor rod 8 executes only a single stroke for the positioning of
all carriages 6. All carriages 6 are coupled on in the starting position
and are "left standing" in their preselected rated position during the
stroke.
The respective top cutters 5 at the carriages 9 are thereby also en-
trained, so that these are also situated in their new positions ready
for interaction with the ledger [or: bottom blades 4.
As may be seen from FIGS 4 and 5, the ledger [or: bottom] blade carriage
6 comprises a motor carrier 29 which [in turn] comprises a hose plate 31
extending parallel to the front of the rail 7 as well as a supporting
plate 32 perpendicular thereto and to the supporting rail 7, these being
additionally connected to one another by means of reinforcing angles 33.
The blade motor 35 is secured to the supporting plate 32 via screws 34.
At its front side distanced from the machine frame M, the rail 7 comprises,
according to FIG 5, a circular cross-section guide rod 36 disposed at
the right outside of the rail 7 and extending over the entire length
thereof, a ball-type nipple 37 which is disposed in a cleat 38 at the
underside of the base plate 31 being seated in said ball-type nipple.
A guide strip 39 projects at the opposite side, i.e. toward the left in
FIG 5, a roller 51 pressing against the underside thereof, said roller 51
being seated in a carrying member 52 which is likewise secured to the
underside of the base plate 31.
The carriage 6 is thus guided in longitudinal direction at the guide rod
36 and is supported against a rotation in accord with FIG 5 toward the
right by means ox thy roller 51. So that the carriage 6, however, while
rotating toward the left, does not lie against the front side of the
rail 7 and drag along it, a further roller 54 is provided a a pedestal
53, said further roller 54 running on the front side of the conveyor
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rail 7 and [being seated in part at the same time in front of the con-
voyeur rod 8 disposed in the rail 7 which is longitudinally displaceable
relative thereto and retaining said conveyor rod 8 in the recess 55 of
the rail 7.
The locking and unlocking fixture referenced 50 overall is secured to
the base plate 31, said fixture 50 being designed as a piston/cylinder
unit comprising a cylinder 60 and a piston I comprising piston rods
61,61 protruding toward both sides. Two cylinder chambers 57,58 are formed
in the cylinder 60 at opposite sides of the piston 56. The cylinder
chamber 58 is outwardly limited by a piston 63 likewise guided in the
cylinder 60 and penetrated by the piston rod 62 and carries a friction
lining 64 at its front side which can lie against the front side of
the rail 7.
The solenoid valve 30 already mentioned with reference to FIG 1 is
a two-position valve via which a compressed air source 59 is selectively
connectable to the cylinder chambers 57,58. In the position of FIG 6,
the cylinder chamber 57 is connected and the piston 56 is pressed down,
so that the index cog 65 engages into the index bore 66 of the conveyor
rod 8. The locking and unlocking fixture 50 is connected to the conveyor
rod 8 in this fashion and is entrained by the latter when it moves, so
that the entire carriage 6 is correspondingly displaced.
In the position of FIG 7, the cylinder chamber 58 is connected to the
compressed air source 9 and the piston 56 is pressed up. Simultaneously,
the piston 63 is pressed down and presses the friction lining 64 against
the front side of the rail 7. The roller 51 is supported against these
forces. In this operating condition, the carriage 6 is fixed against the
rail 7 via the friction lining So and the index cog 65 is released from
the conveyor rail 8.
Governing different positions of the cutting edge 19 at a specific
carriage 6 shall now be explained with reference to FIGS 8 through 12.
A pair of blades 4,5 has again been shown in FIG 8, whereby the cutting
edge 19 is formed by the end face of the ledger [or: bottom] blade 4.
A measuring piece 67 is attached to the supporting plate 32 of the
carriage 6, whereby the radial distance 68 of the outside surface from
the axis of the ledger ion: bottom blade 4 is identical to the radius
thereof. A reference edge whose position corresponds to the position of
the cutting edge 19 is fashioned at what is the right-hand lateral face
of the measuring piece 67 according to FIG 8.
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As derives from FIG 9, the CUttillg edge I and the reference edge 69
have a specific distance 70 from Qn2 another given a new ledger [or-
bottom] blade 4.
When the ledger ion: bottom] blade 4 has then be reground, the distance72 between the edges 19,69 has become smaller by the amount 71 that has
been ground off, as may be seen from FIG 10. The ground-off thickness 71
has been shown with exaggeration in FIG 10; in reality, it is a matter
of amounts on the order of 1 to 2 mm.
In the condition. according to FIG 10, thus, the position of the cutting
edge 19 relative to the reference edge 69 or, respectively, the carriage
6 has become different overall. If the carriage 6 were thus to be post-
toned at the same location, the cut in the paper web would occur at
a location which is wrong by the amount 71.
In order to prevent this, the amount 71 is automatically incorporated
into the control. To this end, position sensors 80 which emit an elect
tribal signal when they are reached or passed by the edges 19 or, resee-
lively, 69 are provided right outside of the ledger [or: bottom blade
4 or, respectively, the measuring piece 80~ In the fashion to be seen
from FIG 5, the position sensors 80 are attached immediately outside of
the measuring piece 67, being attached stationary in the apparatus to
a strip 87 proceeding continuously across the web width which is disposed
on supports 86.
When, thus, the ledger [or: bottom blades 4 have been replaced or no-
ground and have also been remounted on the carriages 6, the carriages 6
are conducted past the position sensors 80 in the direction proceeding
from left to right in FIG 8. The signal 73 (19) shown at the top in
FIG 12 thereby arises in the position sensor 80 when the cutting edge 19
passes and the signal 74 (69) arises when the reference edge 69 passes.
The signals are supplied via the line 75 to the microprocessor controller
100 of the apparatus. At the some time, the microprocessor controller 100
receives the signals of the pulse generator 45 at the drive of the con-
voyeur rod 8 via the line 48. These signals are schematically indicated
in the center in FIG 12 and are referenced 76. The pulse 73 (19~ now
places a counter unit in the microprocessor controller 100 in operation,
this being in turn shut off by the second pulse 74 (69~ and counting the
pulse set 77 shown at the bottom in FIG 12 there between. The pulse sex 77
deriving upon initial installation of the apparatus is stored in the
microproce son controller 100 for each and every carriage 6. After a no-
placement or, respectively, a regrinding of the ledger [or: bottom]
blades 4, the pulse set 77 then deriving is again counted and compared
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to the original pulse set 77. A deviation in the number of pulses
corresponding to the distance 71 then derives, this being automatically
input into the control of the motor operator Al. The motor operator 41
then does not position a specific carriage 6 in its original position
which corresponds to FIG 9 and which would yield the deviation 71 of
the position of the cutting edge lo from the desired cut line 90, but
is positioned in the position shown in FIG if in which the cutting edge
lo is again placed on the desired cut line 90.
The correction of the position of the cutting edge lo ensues automatically.
In order for the microprocessor controller lo to distinguish between
the pulses referenced 73(19) and 74(69) in FIG 12 which axis when
passing the position sensors 80 allocated to each and every carriage 6,
the position sensors 6 are not all identically positioned relative to
the carriages 6 in terms of their control-oriented initial positions
but, as may be seen from JIG 3, are offset from the reference edge 69
of each and every carriage by the distances 81, By, ...85 toward the
right, the distance 82 thereof being greater by a defined amount than
the distance 81, the distance 83 being greater by the same amount than
the distance 82, etc. When, thus, all carriages 6 are coupled to the
conveyor rod 8 and this is steadily displaced toward the right in accord
with FIG l, the pulses of the individual position sensors 80 successively
arrive in the controller lo and do not overlap, so that the controller
can allocate the various pulses to unequivocally defined carriages 6.
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