Note: Descriptions are shown in the official language in which they were submitted.
13332~
Background of the Invention
This invention relates generally to systems and
processes for mounting and very accurately positioning rotating
rolls acting in cooperation with an opposed anvil roll on a
material or web passing through the roll nip. More
specifically, it relates to a roll mounting and positioning
system for inline web finishing equipment for use in
conjunction with a web printing press.
Rotary die cutters are well known for cutting
o apertures of various sizes and shapes in a running web,
particularly a web operating in conjunction with a printing
press. A classic application of such die cutters is to cut out
a set of peel-off labels carried on a backing sheet. Reduced
to its essentials, known rotary die cutters utilize a pair of
rolls rotating about two parallel axes that are rotatably
mounted between a pair of side frames and driven by a line
shaft which also powers the printing press. One roll,
designated as the die roll, or cylinder, carries flexible sheet
metal dies on its outer surface which are the cutting members.
Each die is formed from a thin metal sheet and has raised
cutting edges formed in the shape of an aperture to be cut.
The die is wrapped around the die cylinder and replaceably
--2--
13~32~
1 secured to it, usually utilizing magnetic attraction produced
by embedded permanent magnets in the die cylinder. Dies can
also be secured by tapes, mechanical clamps, or other types of
fasteners. The anvil cylinder is formed of a hardened material
and is of such diameter that its surface speed is substantially
equal to web speed.
As the web passes between the rotating cylinders, the
cutting edges of the die are pressed into the web backed up by
the anvil cylinder to produce the desired aperture in the web.
lo To the best of applicant's knowledge, heretofore such rotary
die cutters, at least when used in printing press applications,
have always end-mounted both the die roll and the anvil roll
and side frames. Because the web leaving the printing press
has a substantial width, a significant problem has been the
deflection of the die roll caused by operating forces, machine
distortions, vibrations, and thermal expansions. The
traditional solution has been to utilize a roll having a
sufficiently large diameter that it is able to resist any
significant deflection. This works, but the necessary roll
diameter has been such that for most product lengths (cut-offs)
there is a "double repeat", that is, the image or pattern being
printed is repeated during one revolution of the die cylinder.
The disadvantage of this solution is that a die
--3--
!' `
133325 ~
cylinder with a double repeat diameter is massive and costly to
manufacture, particularly where the outer surface of the die
cylinder must be machined to extremely tight tolerances. In
addition, the substantial rotational inertia of such a large
diameter die roll is an impediment to achieving a fast stop of
the printing line during an emergency stop.
Other disadvantages relate to the need to have the
apertures extremely accurately located so that they are in
registration with the pattern printed on the web. A "vertical"
o adjustment of the die, one affecting the spacing between the
die and anvil rolls, is also important to adjust the spacing
between the cutting edges of the die and the anvil cylinder.
This is important, for example, so that the die achieves a
reliable cut in the web, the cutting edge does not strike the
anvil cylinder and become dulled or damaged, and so that the
correct spacing occurs across the full length of the die roll.
In addition, as is well known to those skilled in the art, even
when proper adjustments in the position of the dies are made,
changes in factors such as the web material, wear of the die,
and shifts in the relative position of comp~nents due to
thermal expansion can re~uire periodic readjustments of the die
positions in order to have reliable apertures continue to be
cut in the web.
--4--
13 ~ 3 2 ~i ~
1 In the prior art systems, the principal technique
currently used to adjust the vertical position of a die with
respect to a die roll is to place a shim between the die and
the roll manually. This is a tedious and time-consuming
procedure since the shims must be positioned with the die
cutter stopped, the selection and placement of the shim is to
some extent guesswork, and then the adjustment must be measured
or tested by operating the die cutter to observe the effect of
the adjustment. Not only does this procedure suffer from the
lo fact that it is manual and requires at least a modest degree of
skill, but also it requires that the printing press be stopped
while the adjustments are made and checked. As is well known,
any stoppage of the press is costly in terms of lost
productivity. In addition, in placing the shim there is always
a risk that the correct axial or circumferential positioning of
the die in the roll may be lost requiring still further
adjustments. It is aiso very important to note that the
positioning must be controlled to extremely tight tolerances.
Typically, control to one-tenth of a mil (0.0001 inch) is
reguired.
Another known technigue for changing the axis-to-axis
(vertical) spacing of the rolls is to mount at least one of the
rolls on an eccentric so that its center line location can be
--5--
133325~
1 varied between two extreme positions. Such adjustments cannot
be made on the run, that is, while the press is running and the
web is passing through the rotating die cutter cylinders.
Axial and circumferential adjustments of the die also require
that the press be stopped while the die position is manually
shifted on the die cylinder and reset. The adjustment process
is manual, time-consuming, and cannot be made on the run.
Also, eccentric adjustments do not provide the fine degree of
adjustment often required to compensate for wear or the other
lo factors listed above. When eccentrics have been used while the
rotary die cutter is operating, they have been used most often
to move the die roll a substantial distance to go "off
impression", that is, moving the die cylinder away from the web
to allow operation of the press line without operation of the
die cutter.
It is also significant to note that conventional
rotary die cutters utilize only one die cylinder and that the
only practical way to adjust the axial or side-to-side position
of the web is to shift the lateral position of the web as it
passes through the cutter. This web shift works, but it has a
significant disadvantage in that it reguires that all of the
other pieces of equipment in the line, such as gluers,
perforators, numbering machines or plow stations, also be
--6--
133~2~5
1 adjusted with respect to the web to maintain registration.
This multiple adjustment of a series of machines to the web
shift is time-consuming and tedious. However, no rotary die
cutters presently known to applicants are capable of an axial
or "sidelay" adjustment of the cutter.
It is therefore a principal object of this invention
to provide a mounting and positioning system for a rotary die
cutter which utilizes a small diameter, single repeat roll and
yet which exhibits extreme rigidity.
lo Another principal object of the invention is to
provide a mounting and positioning system with the foregoing
advantages which provides extremely accurate positioning of the
die with respect to the web and its anvil roll, vertically,
axially, and circumferentially.
Yet another principal object of the invention is to
provide a rotary die cutter positioning and mounting system
with the foregoing advantages where the foregoing adjustments
can be made with extreme accuracy, independently of one
- another, and while the die cutter is operating.
A further object of the invention is to provide a
rotary die cutter mounting and positioning system which can be
set up or adjusted within extremely short make ready time as
compared to conventional systems currently in use.
_~_
133325~
1 Still another object of the invention is to provide a
mounting and positioning system for a rotary die cutter which
can mount two or more die rolls in an axially spaced
relationship operating in cooperation with the same anvil where
each die roll can be adjusted vertically and axially
independently of the other with all of the foregoing advantages.
Another object of the invention is to provide a roll
- positioning and mounting system for a rotary die cutter for use
in connection with a printing press which can handle a full
lo width web offset, or can simultaneously run jobs having
different dies or die patterns side-by-side.
A further object of the invention is to provide a
mounting and positioning system for a rotary die cutter which
has a reduced rotational inertia as compared to prior art
devices and therefore can be brought to an emergency stop more
quickly.
Still another object is to provide a mounting and
positioning system for a rotary die cutter which has a
favorable cost of manufacture and which requires fewer dies for
operation since the pattern can be completed once every
revolution rather than twice as was the case with prior art
devices.
Yet another advantage is to provide a mounting and
--8--
1~332~
1 positioning system with the foregoing advantages which also
provides a rapid off-impression capability.
Summary of the Invention
The present invention involves a mounting and
positioning system for a roll, particularly a die roll of a
rotary die cutter used for inline web finishing in conjunction
with a web printing press. The die roll is operated in
conjunction with an opposed anvil roll. The axes of rotation
lo of the die and anvil rolls are parallel. The die cutter of the
present invention utilizes a pair of extremely rigid side
frames, typically frames formed of 2 1/2 inch thick steel, and
an extremely rigid spreader, preferably a hollow steel beam
with a generally square cross section, which extends between
and is secured to the side frames. The anvil roll is rotatably
mounted directly in the side frames.
At least one, preferably two, axially spaced and
co-axial die rolls are rotatably mounted in bearing blocks
supported from the spreader, not end-mounted-in the side
frames, to separate the drive for the rolls from the
positioning of the rolls. The die rolls have a comparatively
small diameter, typically a single repeat roll when used with a
web printing press, and preferably are comparatively short,
_g _
133~25~
1 with the length being comparable to the die circumference. In
the preferred form, the bearing blocks, and the die rolls
mounted in the bearing blocks, are adjustably mounted with a
compliant clamping to provide a well-controlled and precise
adjustment of the vertical position of the die roll. The
bearing blocks are preferably secured to a bed plate having
side rails which receive a set of clamping bolts. A stack of
Belleviile springs is captured under the head of each bolt to
produce a compliant, vertically-directed clamping that
lo maintains a solid, metal-to-metal contact between the spreader
and the die roll through the parts interposed between them.
This solid clamping faithfully transmits the rigidity of the
spreader to the die roll. A horizontal movement of an opposed
pair of wedges with mating inclined faces, acting on the bed
plate, produces a uniform vertical adjustment in the position
of the die roll acting against the compliant clamping. A
pneumatic actuator acting on the wedges provides an
off-impression capability which does not lose the original
precise positioning of the die roll after it returns to its
on-impression position.
A horizontally oriented screw translates a follower
block to adjust the axial position of the die roll. In the
preferred form, the axial adjustment mechanism includes an
--10-- `
133325~
axially extending slideway having downwardly sloped outer side
surfaces which mate with and capture a pair of dovetail guide
rails secured to a fixed one of the wedges. In this preferred
form, an outwardly extending flanged portion of each dovetail
rail receives the vertical clamping bolt and the Belleville
spring stack.
Rotary drive power is transmitted from a printing
press lineshaft to the die cylinders and the anvil roll through
a gear train. The transmission includes a planetary gear box
o which is coupled between the lineshaft and a drive shaft for
the die roll, or rolls. A motorized drive adjusts the angular
position of the planet gears with respect to the lineshaft to
produce a corresponding adjustment in the circumferential
position of the die roll with respect to the web.
The drive shaft is generally co-linear with the axis
of rotation of the die rolls. However, it and the die rolls
are structured so that it transmits a driving or positioning
adjusting rotation. In particular, the die rolls are not fixed
on, or integral with, the drive shaft, as is the case with
commercial ~rior art arrangements. The die rolls are free to
slide axially along the drive shaft to the control of the
adjusting lead screw and to move vertically, within
predetermined maximum limits, under control of the
--11--
133~2~5
aforement~oned vertical ad~ustment system, ~ncluding a pair of
opposed wedges. A preferred arrangement for achieving these
operational characteristics includes a plurality of ~plines
which extend axially along the outer surface of the drive shaft
and are received in mating, oversized recesse~ formed in the
body of the die roll that couple the die roll to the drive
shaft.
Stated as~a process for mounting and positioning a
single roll with respect to a fixed anvil roll, the process
involves steps of providing a pair of rigid side frames,
providing an extremely rigid spreader extending between the
side frames, providing a small diameter, single repeat roll
whose width is less than a spacing between the side frames,
driving the die roll in a rotating motion where the drive only
transmits a positive rotation to the die roll, but otherwise
leaves it uncoupled for adjusting movements ~ith two degrees of
freedom, and independently adjusting the position of the die
roll axially, vertically, and circumferentially.
Accordingly, in one aspect, the present invention
relates to a mounting system for a roll operating in conjunction
with an anvil roll where the roll and the anvil roll rotate about
parallel axes, comprising
a pair of very rigid side frames,
a spreader mounted between the side frames that is
substantially inflexible,
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133325~
1 means for driving said roll and said anvil roll to
rotate about their respective longitudinal and substantially
parallel axes, said driving means comprising
a drive shaft that extends between and is
rotatably mounted in said frames, and
means for operatively coupling said roll and said
drive shaft, said coupling means comprising
axially extending splines on said drive shaft and
a central longitudinally extending passage in said roll having
complementary mating recesses oversized with respect to the
cross-sectional dimensions of the associated ones of said
splines,
said coupling means transmitting only a rotation,
while otherwise permitting movement of said roll with respect to
lS said drive shaft vertically and axially,
means for supporting said roll from said spreader, said
driving means and said supporting means being independent so that
said driving means transmit only a rotation to said roll, wherein
said supporting means has means for creating a precise adjustment
of the vertical position of said roll and means for compliantly
clamping said vertical position adjustment means to transmit the
rigidity of said spreader to said roll.
In a further aspect, the present invention relates to a
mounting system for a roll operating in conjunction with an anvil
-12A-
C
13332~
1 roll where the roll and the anvil roll rotate about parallel
axes, comprising
a pair of very rigid side frames,
a spreader secured between the side frames that is
substantially inflexible,
means for driving said roll and said anvil roll to
rotate about their respective longitudinal and substantially
parallel axes said drive means including a shaft supported at its
ends in said side frames and passing freely through the roll, and
lo means mounted on said spreader for supporting said roll
rotatably and rigidly with respect to movement along a line
perpendicular to and coincident with both of said parallel axes
of rotation while not being supported by said driving means
including said shaft,
said driving means and said supporting means being
independent so that said driving means transmits only a rotation
to said roll.
In another aspect, the present invention relates to a
process for mounting and positioning a roll operating on a web
passing between it and a rotatable anvil roll comprising
providing a pair of rigid side frames,
providing a rigid spreader extending between said side
frames,
providing bearing blocks for said roll,
-12B-
C~
1~3325~3
1 rotatably mounting said roll in said bearing blocks,
mounting said bearing blocks on said spreader within
said side frames,
driving said roll to transmit only a rotation without
interfering with or controlling the location or adjustment in
location of said roll with respect to said side frames or said
spreader, including
connecting to a line shaft,
providing means for transmitting rotation to a
0 drive shaft, and
operatively coupling said drive shaft to said
roll, wherein said circumferential adjusting comprises adjusting
the instantaneous angular relationship with respect to that of
said line shaft by adjusting said transmitting means, and
adjusting the circumferential position of said
roll with respect to the web, said circumferential adjusting
being independent of said driving and independent of the
positioning of said roll in any other degree of freedom.
In still a further aspect, the present invention
relates to a process for mounting, positioning and rotating a
roll operating on a web passing between it and an anvil roll
rotatable about a first axis comprising
providing a pair of rigid side frames,
providing a rigid spreader extending between and
-12C-
1~332~
1 secured rigidly to said side frames,
providing bearing blocks for said roll,
mounting said roll in said bearing blocks to rotate
about a second axis generally parallel to said first axis,
driving said roll to transmit only a rotation without
interfering with or controlling the location or adjustment in
location of said roll with respect to said side frames or said
spreader, said driving including providing a shaft supported at
its ends in said side frames and passing freely through said roll
~ without providing any support to said roll, and
mounting said bearing blocks on said spreader between
said side frame whereby said roll is mounted rigidly with respect
to movement away from the anvil roll without being supported by
said shaft.
These and other features and objects of the foregoing
invention will be more readily understood with reference to the
following detailed description of the preferred embodiments
which should be read in light of the accompanying drawings.
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( (
13~32~
1 Brief Description of the Drawings
Fig. 1 is a simplified perspective of a rotary die
cutter according to the present invention having two co-axial
die rolls driven by a common drive shaft and co-acting with a
common anvil cylinder;
Fig. 2 is a view in front elevation, and partially in
vertical section, of the rotary die cutter shown in Fig. 1 with
a control panel removed and showing associated additional rolls
and the drive system for rotat;ng all of the rolls illustrated;
lo Fig. 3 is a view in side elevation and partially in
vertical section, with portions broken away, of the rotary die
cutter shown in Figs. 1 and 2;
Fig. 4 is a detailed view in vertical section of a die
roll and its associated drive shaft taken along line 4-4 in
Fig. 2; and
Fig. 5 is a detailed view in vertical section of the
compliant clamping arrangement for the die rolls to transmit
the rigidity of the spreader to the die roll or rolls despite
the vertical adjustability of the mount for each die roll.
Detailed Description of the Preferred Embodiments
Figs. I - 3 show a rotary die cutter assembly
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133325~i
according to the present invention which is adapted
particularly for use on line in conjunction with a web printing
press to produce a pattern of apertures in a web W being
printed. The die cutter assembly 10 includes a pair of
~ generally upright and extremely rigid side frames 14,
preferably formed of steel having a thickness of approximately
2 1/2 inches that are bolted or otherwise secured to the ground
or floor. A massive and extremely rigid spreader 16 extends
~etween and is secured to the frames 14,14 at their upper end
to produce an extremely rigid parallelogram frame assembly.
The spreader 16 is preferably formed of a hollow steel member
having generally rectilinear cross section, as best seen in
Fig. 3. The walls of the spreader 16 preferably have a
thickness of at least 1/2 inch formed of steel. The side
frames 14,1~ and the spreader 16 are sufficiently rigid that
they exhibit negligible deflection in response to operating
forces, machine distortions, and machine vibrations. In the
preferred form shown, the frame also includes a second spreader
16', similar in construction to the spreader 16, and also
secured between the side frames 14,14, but located below the
anvil roll 18.
An anvil roll 18 is end mounted directly in bearing
assemblies 20,20 which are in turn mounted in the side frames
-14-
1333255
14,14. The anvil roll of a type conventional in the industry
is formed of hardened steel of a sufficient diameter to resist
deflection.
Principal features of the present invention are a pair
of die rolls 20,20 supported and positioned by mounting
assemblies 22,22 all of which are bolted to the bottom of the
spreader by bolts 24 (Fig. 3). A drive shaft 26 journaled in
bearing assemblies 28,28 end-mounted in the side frames 14,14
transmits a torgue to rotate the die rolls 20,20 in
coordination with the movement of the web through a nip 30
between the die rolls and the anvil cylinder 18. The die rolls
each carry at least one die 31 having at least one raised
cutting edge 31a that cuts the desired aperture in the web. As
shown, the dies are thin metallic sheets of conventional design
and are secured to the die roll magnetically using well known
techniques.
It is a significant aspect of the present invention
that while the spreader and drive shaft are end-supported in
the side frames, the die rolls are not rigidly secured to the
drive shaft 26 and can be moved axially with respect to the
drive shaft independently of one another, as well as adjusted
vertically, where "vertical" means the plane defined by the
axes of rotation of the die rolls and the anvil roll as
-15-
c`~
13332~5
indicated by the arrow 34. It is also significant that the die
rolls 20,20 can exhibit extreme rigidity when subjected to web
cutting forces (usually in excess of 200 pounds/inch for a line
cut), while having a comparatively small diameter, typically
one yielding a circumference that is equal to only a single
repeat of the pattern being printed on the web. Preferably the
die rolls are also comparatively short, with a length of
approximately the same as the circumference.
The mounting assembly 22 is clamped and vertically
o adjustable utilizing a pair of wedges 36a and 36b each having
an inclined, mating cam surface 36c. As shown, the wedge 36a
is fixed with respect to the spreader. The wedge 36b, however,
is movable laterally in the direction of arrow 38, which
produces a uniform change in the vertical position of a bed
plate 40 with respect to the spreader 16. As is best seen in
Figs. 2 and 3, the bed plate 40 has a groove 40a which receives
a mating-tongue 36b' of the movable wedge 36b to guide the
translation along the direction 38. This direction is
perpendicular to the axis of rotation of the die rolls 20 and
oriented with respect to the inclination of the wedge surfaces
36c to maximize the vertical camming motion of the wedges in
response to a given horizontal relative motion between the
wedges 36a, 36b. The change in the vertical displacement of
-16-
c~
13332~
the wedges i8, of course, reflected in corresponding vertical
movement of components such as the bed plate 40 secured to or
otherwise movable vertically in unison with the wedge 36b. A
pneumatic actuator 41 acting through a bearing assembly 41a
rapidly drives the movable wedge 36b between two limit
positions. In one limit position, as shown, the die roll is
positioned and adjusted so that the dies 31 are in a cutting
relationship with respect to the anvil roll ("on impression").
In another limit position, corresponding to a horizontal travel
o of about 1/2 inch, the die roll is sufficiently spaced from the
anvil roll that no cutting occurs ("off impression"). The
limit positions are precisely defined by stops so that upon
returning to "on impression" operation, the original position
of the die roll, axially, vertically and circumferentially, is
established with reliability and precision.
Bolts 42 mount bearing blocks 44 which in turn mount
and guide the die rolls 20,20. The bed plate 40 has a pair of
axially extending side rails 48,48 which may be formed
integrally with the bed plate, or secured to the bed plate as
by welding or with bolts. Each side rail 48 extends vertically
a sufficient distance to provide a clearance for the wedges
36a,36b, and rotatably supports a lead screw 50 which is
engaged in a threaded hole 36d formed in the movable wedge
-17-
C~ CJ
13332
36~. Rotation of a hand wheel 52 on one end of the lead screw
sO produces a horizontal translation of the wedge 36b along the
direction 38, and thereby an adjustment in the vertical
position of the bed plate 40 and the die roll 20 with respect
to both the spreader 16 and the anvil roll 18, which are fixed
in position with respect to the side frames 14,14.
The side rails also have threaded holes 48a in their
upper surface which receive bolts 54, as shown in detail in
Fig. 5. The end of each bolt threads into the hole 48a, but
o the bolt has a smooth shoulder portion 54a that passes freely
through (1) an outwardly projecting flange portion 56a of a
dovetail rail 56 and (2) a stack 58 of Belleville springs
captured between a head 54b of the bolt 54 (acting through an
intermediate cap 59 located over the Belleville stack 58) and
the upper surface 56a' of the flange portion 56a. When the
bolt 54 is sufficiently threaded into the hole 48a, the
Belleville washers 58 compress and generate a clamping force
that urges the bed plate toward the spreader and clamps these
members and the wedges 36a, 36b caught between them into a
firm, metal-to-metal contact. This clamping avoids any
resiliency or "play" in the support structures 22,22 so that
the rigidity provided by the spreader is transmitted to the die
~olls 20,20 by the mounts 22,22. The cam action of the wedges
-18-
13332~ j~
1 36a,36b acts in cooperation with this spring clamping to
provide a precisely controlled and highly accurate adjustment
in the vertical position of the die rolls 20,20 through a
rotation of the handwheel 52 and a corresponding rotation of
the lead screw S0. In a preferred form, the pitch of the
inclined surfaces 36c and the pitch of the threads and the lead
screw 50 are such that one complete rotation of the handwheel
52 produces a uniform change in the vertical position of the
die roll 20 with respect to the anvil roll 18 of one mil. The
handwheel 52 is preferably calibrated so that rotation through
36 produces a well-controlled, reliable vertical adjustment in
the position of the die rolls in the order of at least
one-tenth of one mil (0.0001 inch).
Axial adjustment of each of the die rolls 20 is
provided by an axially extending slideway 60 secured by the
bolts 24 to the spreader 16 and having a pair of outwardly
sloped side surfaces 60a,60a which mate with correspondingly
sloped surfaces 56b of the dovetail rails 56. This dovetailing
captures each entire mounting assembly 22, and therefore the
associated die rolls 20, on the slideway 60. A follower block
62 is secured by bolts 65 to the fixed slide 36a. The follower
block has at least one threaded hole 62a which receives a lead
screw 64 rotated by handwheel 66 through a belt or chain 68.
--19--
13332~
1 Each screw is journaled in bearings mounted in the side frames
14,14. Rotation of the handwheels 66,66 rotates an associated
lead screw 64,64 causing an axial movement of the mounting
assemblies 22 and a corresponding axial movement or "sidelay"
of the die rolls 20,20 as the follower block 62,62 thread along
the lead screws 64,64. Each lead screw and follower block
64,62 operates independently on an associated one of the
mounting assembly 22 and its associated die roll 20 so that
there is an independent axial adjust~ent of each die roll.
lo This sidelay adjustment can be made while the press and the
rotary die cutter 10 are operating. To the best of applicants'
knowledge, no prior art rotary cutter is capable of a
comparable sidelay adjustment, let alone a lateral or axial
adjustment of two rotary dies independently of one another.
Power for the rotary cutter originates with a rotating
line shaft drive 70. A mitre gear box 73 transmits rotary
power to a planetary gear train 72 which is coupled through a
conventional belt 74 and pulleys 75,75 to rotate the anvil
cylinder 18.- Gears 77,77 secured on the anvil roll and the
drive shaft 26 mesh so that this drive also rotates the drive
shaft 26, but in a direction opposite to that of the anvil
roll. Because the output of the planetary gear box is coupled
to the drive shaft, an angular rotation of the planet gear
-20-
133325~
1 carrier results in a cor~esponding angular shift in the
position of the drive shaft 26 with respect to the angular
position of the line shaft. This angular phase shift provides
an adjustment in the circumferential position of a die 31
mounted on the outer surface of the die rolls 20,20, thereby
providing adjustment in the position of the aperture cut by the
die in the web W in its running direction. A motor 79 acting
through belt 81 drives a worm gear shaft 80 in the planetary
gear box to produce the desired circumferential adjustment.
Agai~n, it is significant to note that this circumferential
adjustment is independent of the vertical adjustment provided
by the rotation of the handwheels 52 or the axial or sidelay
adjustment provided by the rotation of the handwheel 66,66.
-With particular reference to Fig. 4, the drive shaft
26 has four equiangularly spaced and axially extending splines
26a each secured by a series of screws 26b. Each spline is
surrounded by an oversized recess 20a formed in the body of the
die roll 20 and a central cylindrical passage 20b also formed
in the die roll 20 with a clearance 82 there between. The size0
of the clearance 82 is sufficlent to al,low a free vertical
movement of the roll 20 in the di'rection 34 in response to an
adjustment in the relative positions of the wedges 36a and
36b. The clearance 82 also allows an unencumbered sliding
-21-
f 13332~
movement of the roll 20 along the drive shaft 26 to accommodate
an axial sliding movement in the direction 32. However, the
splines 26a project sufficiently into the associated recesses
20a that regardless of the vertical position of the roll 20,
rotation of the drive shaft 26 causes a positive mechanical
engagement between one edge of the spline 26 with an associated
side wall of a recess 20a to transmit a rotational torque.
With reference to Fig. 2, the mating faces 36c of the
wedges contain a central recess 36d formed in at least one of
the wedges so that the wedges engage one another only at their
edges. This avoids the cost associated with machining what
would otherwise be two relatively large surfaces to an
extremely high degree of flatness. It also promotes lateral
stability of the wedges. At least one of the wedges can
include passages to direct a flow of lubricant to the interface
between the opposed cam surfaces 36c,36c.
In operation, the web W, which may be a continuous
full width web of a conventional width or one or more webs
moving in side-by-side relation, travel through the nip 30 of
the rotary die cutter where the die or dies 31 carried on the
outer surface of the die roll or rolls 20 cuts a pattern of
apertures in the web W that is in registration with the pattern
being printed on the web by the press. The mounting and drive
-22-
13332~S
1 arrangement of the present invention provides extreme rigidity
in the die rolls 20 even though they have a comparatively
small, single repeat diameter. The die rolls 20, while
preferably being sufficiently short that their length i8
comparable to their circumference, extend axially to create a
pattern of apertures in the web W over its full width at all of
the desired locations. Adjustments in the vertical position of
each of the die rolls 20,20 can be made conveniently, and
independently of one another, by rotating the handwheels
lo 52,52. Similarly, a rotation of the handwheels 66,66 adjusts
the axial position of the associated die roll 20,20 on the
run. Further, the location of the apertures formed by the dies
31 can be adjusted in the running direction of the web through
a rotation of the worm gear shaft 80 causinq a corresponding
adjustment in the angular position of the drive shaft 26 with
respect to the web W. After the cuts have been made by the
dies 31, the web W is directed over a very small diameter roll
84 which operates in conjunction with a surrounding suction
head 86 to remove from the web the "chips", or trim, cut by the
apertures 31a of the dies 31.
Stated in terms of a process, the present invention
involves mounting, positioning and driving die rolls with
respect to an anvil roll for processing a web moving through
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the nip between the die roll and the anvil roll where the die
rolls have a comparatively small diameter and yet are extremely
rigid. The process involves the steps of providing rigid side
frames and a rigid spreader extending between the side frames,
mounting the small diameter die roll or rolls from the
spreader, and at the same time driving the die rolls in a
manner that transmits only rotation, but does not significantly
restrict the vertical or axial position of the die rolls with
respect to the anvil roll or the supporting structure. The
lo process of the present invention also includes adjusting the
position of the die roll or rolls vertically, axially, and
circumferentially where these adjustments are independent of
one another.
There has been described a system and process of
mounting and positioning a rotary die cutter where a small
diameter, single repeat roll provides extreme rigidity and can
be positioned with a high degree of precision vertically,
axially, and circumferentially with respect to the web and
opposed anvil roll. The foregoing mounting and positioning
system process provides a substantial reduction in the
make-ready time of the rotary cutter as compared to
conventional systems, can handle a full width web and can run
different jobs on different webs side by side, simultaneously.
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1333255
1 The present invention also has a favorable cost of manufacture
as compared with conventional rotary die cutters, can be
brought to an emergency stop quickly, and has an off-impression
capability while preserving all of the aforementioned
advantages.
While the invention has been described with respect to
its preferred embodiments, it will be understood that various
modifications and alterations will occur to those skilled in
the art from the foregoing details in combination ~ith the
lo accompanying drawings. For example, the invention has been
described with respect to a rotary die cutter for use in
connection with inline web finishing equipment operating in
conjunction with a web printing press. It can also be applied
to other roll-type apparatus acting on webs such as gluers,
pattern perforators, rotary cutters and imprinters such as
numbering, bar-coding and embossing apparatus.
Further, while the system has been described with
respect to a roll or rolls which are suspended from a spreader,
it will be understood that the die roll or rolls could be
mounted above a spreader to act on a web or material passing
through a nip above the die roll. Also, while the invention
has been described with respect to a pair of die rolls acting
in cooperation with a fixed anvil roll, die rolls mounted and
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133325~
configured according to the present invention can operate in
opposition to one another and the invention includes three or
more die rolls mounted and operating in a manner described
hereinabove. Further, while various specific mechanical
arrangements have been described for producing the adjustment
of the vertical, axial and circumferential positions of the die
roll or rolls with respect to the web, it will be understood
that a wide variety of other eguivalent mechanical arrangements
will occur to those skilled in the art in view of the detailed
lo description of the present invention. These and other
variations and modifications are intended to fall within the
scope of the appended claims.
What is claimed is:
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