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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to signature folding devices for
web-fed printing presses and, more particularly, to a folder apparatus
which allows on-the-fly adjustment of the folding operation to accommodate
different press speeds and variable signature sizes.
2. Discussion of the Prior Art
In a conventional signature folder designed for use with web-fed newspaper
or large publication presses, a number of folding stations are provided
for producing a single, fixed-size product.
Typically, an upstream folder cuts the web into sheets and folds the web
along a line extending in a direction transverse to the web. This
cross-folded signature is then delivered onto a conveyor and can, if
desired, be folded again along a line extending in a direction transverse
to the cross fold line. The subsequent fold is formed by a chopper, which
is a thin piece of spring steel that is lowered onto each signature as it
travels along the conveyor, forcing the signature between two inwardly
rotating rollers.
In order to properly align each signature with the chopper, it is known to
provide a stationary head stop extending across the conveyor within the
travel path of the signatures so that each signature strikes the stop and
is squared relative to the chopper prior to the chop-folding operation so
that it will be folded accurately.
If the head stop is not properly positioned along the conveyor, the
signatures approaching the chopper will either be engaged by the chopper
before striking the head stop, in which case the signatures are not always
square, or strike the head stop with such force as to damage the
signature, e.g. by bending the corners over or the like.
Thus, it is necessary to determine where the stop should be positioned
along the conveyor in order to stop and square the signatures without
damaging them. Unfortunately, once the head stop is adjusted for use at
any particular press speed, it is not suitable for other press speeds. For
example, if the stop is mounted in a position suitable for a given press
speed, and the speed is increased, the signatures traveling on the
conveyor have greater momentum, hitting the stop harder. Thus, damage to
the signatures occurs unless the device is first shut downs and the
position of the head stop is adjusted for the new press speed.
Another solution is to adjust the timing of the chopper movement relative
to the moving signature so that the chopper engages the signature after
the signature is squared but before the momentum of each signature carries
it into the head stop with so much force as to cause damage to the
signature. Although this solution reduces or eliminates down time of the
press, it requires a special variable mechanical transmission and
increases the cost of the press substantially.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a signature folder
apparatus for use with various sizes of signatures, wherein relatively few
parts are employed so that setup and maintenance of the apparatus are
simplified.
It is another object of the present invention to provide an apparatus
including means for adjusting the position of each signature relative to a
chopper folder so that the signatures are protected against damage during
alignment with the chopper, and high quality products are produced.
It is yet another object of the present invention to provide a folder
apparatus within which each cross-folded signature is supported during a
subsequent folding operation in order to prevent the signature paper from
whipping freely during the operation.
In accordance with these and other objects evident from the following
description of a preferred embodiment, a sheet folding apparatus is
provided for use with a web-fed printing press, wherein the apparatus
includes an upstream folding means for cutting the web into sheets and
cross folding each sheet along a fold line extending in a direction
transverse to the length of the web, a conveyor means for delivering the
cross-folded sheets from the upstream folding means along a delivery path,
and a downstream folding means positioned along the delivery path for
chop-folding the cross-folded sheets along a fold line extending in a
direction transverse to the cross fold line, and for delivering the
chop-folded sheets from the apparatus.
A head stop is positioned within the delivery path of the apparatus for
limiting the movement of the sheet along the path and for positioning the
sheet relative to the downstream folding means. The position of the head
stop along the delivery path is adjustable during operation of the
apparatus so that such adjustments may be made on the fly to accommodate
variable press speeds.
In accordance with another aspect of the present invention, a drive means
is provided for driving the upstream folding means, and a transmission
means transmits the drive of the upstream folding means to the downstream
folding means. A cassette supports the upstream folding means and is
removable from the apparatus to allow replacement of the cassette and of
the upstream folding means. In addition, the downstream folding means may
be enabled and disabled independently of the upstream folding means. A
registration means is provided for registering the two folding means with
the transmission means and with each other so that after the cassette is
replaced or the downstream folding means is enabled, the two folding means
may be registered with one another. In addition, the registration means
provides registration between the folder apparatus and the upstream
web-fed printing press.
By providing a signature folder apparatus in accordance with the present
invention, numerous advantages are achieved. For example, by permitting
adjustment of the position of the head stop along the delivery path, it is
possible to locate the head stop so that the signature is stopped and
squared relative to the downstream folding means without being damaged. In
addition, by enabling this adjustment to be made during operation of the
downstream folding means, no down time of the apparatus is required, and
it is possible to adjust the position of the head stop to accommodate
changing press speeds, variable signature sizes, and different folding
configurations without adversely effecting production.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
A preferred embodiment of the present invention is described in detail
below with reference to the attached drawing figures, wherein:
FIG. 1 is a side elevational view of a signature folder constructed in
accordance with the preferred embodiment of the present invention;
FIG. 2 is a fragmentary top plan view of the apparatus, illustrating a
downstream folding assembly of the apparatus;
FIG. 3 is a fragmentary sectional view taken along line 3-3 of FIG. 2;
FIG. 4 is a fragmentary side sectional view similar to FIG. 3, illustrating
an adjusted position of a slide plate assembly associated with the
downstream folding assembly;
FIG. 5 is a fragmentary sectional view taken along line 5-5 of FIG. 1;
FIG. 6 is a fragmentary sectional view taken along line 6-6 of FIG. 1;
FIG. 7 is a fragmentary sectional view of an upstream folding assembly;
FIG. 8 is a side elevational view of a cassette on which the upstream
folding assembly is supported;
FIG. 9 is a fragmentary side elevational view similar to FIG. 1,
illustrating the use of a replacement cassette in the upstream folding
assembly to vary the size of the signatures to be folded by the apparatus;
and
FIG. 10 is a perspective view of a signature in the various stages of
folding as carried out by the apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred construction of a folder apparatus for use with a web-fed
printing press is illustrated in FIG. 1, and broadly includes an
upstanding frame 10 on which an upstream folding assembly 12, an
intermediate conveyor assembly 14, a downstream folding assembly 16, and a
delivery conveyor 18 are supported.
As illustrated in FIG. 2, the frame includes a pair of spaced side walls
20, 22 on which the assemblies 12, 14, 16 are mounted. Preferably, the
frame is adapted to be arranged at the delivery end of a web-fed printing
press so that the printed web delivered from the press is fed directly to
the folder apparatus. As illustrated in FIG. 7, the web is then trained
through the upstream folding assembly 12 where the web is cut into sheets,
and cross folded along a fold line extending in a direction transverse to
the length of the web.
Thereafter, the cross-folded sheet is conveyed to the downstream folding
assembly 16 where it is folded along a fold line extending in a direction
transverse to the cross fold line before being delivered from the
apparatus. This progression from web to sheet and from sheet through
multiple folding operations is illustrated in FIG. 10.
The upstream folding assembly is illustrated in FIG. 7, and includes a
tucker cylinder 24, a gripper cylinder 26, and a conveyor 28, all of which
are supported between the two side walls 30 of a cassette which is
removable from the frame so as to enable replacement of the
assembly.degree. Although only a single folding station is illustrated in
the upstream folding assembly, it is noted that multiple folding
operations can be carrier out by adding additional stations or cylinders.
The cassette is adapted to fit within and engage the frame of the
apparatus, and is equipped with a plurality of concave wheels 32 which
extend slightly below the side walls 30 so that the cassette can be moved
along complementary rails 34 extending between and secured to the walls of
the frame 10. U.S. Pat. No. 5,060,569, issued 29 Oct. 1991, relates to an
apparatus for changeover of cylinders in a web-fed printing press, and
discloses the use of a cassette structure of the type preferably employed
in the present folder apparatus. This patent disclosure is incorporated
herein.
The tucker cylinder 24 includes a tucker 36, which is a thin piece of
spring steel extending the length of the cylinder and protruding slightly
from the surface of the cylinder. Opposing the tucker on the tucker
cylinder is a row of pins 38 and a cutting edge 40, both of which extend
longitudinally of the cylinder and protrude slightly from the cylinder
surface. The gripper cylinder 26 includes a row of jaws 42 and a
conventional mechanism for opening the jaws as they come into registration
with the tucker 36 so that a signature supported on the tucker cylinder is
pressed into the jaws by the tucker and carried with the gripper cylinder
26.
Opposing the jaws on the gripper cylinder 26 is a backup member 44 which
registers with the row of pins 38 and cutting edge 40 of the tucker
cylinder, enabling the signature carried on the tucker cylinder to be cut
so that it may be carried on the gripper cylinder from the assembly. At
the same time, the row of pins 38 engage the free end of the web, holding
the next signature against the tucker cylinder until the signature is
gripped, cut and pulled from the tucker cylinder by the gripper cylinder.
The conveyor 28 defines a nip with the gripper cylinder 26 and presses the
signature against the gripper cylinder so that the signature is compressed
along the fold line to complete the cross folding operation on the sheet.
In addition, the conveyor delivers each cross-folded signature to the
intermediate conveyor assembly, as shown in FIG. 3 so that the signature
may be transported to the downstream folding assembly 16.
Turning to FIG. 3, the intermediate conveyor assembly 14 includes a lower
conveyor 46 including a plurality of conveyor belts trained about two
spaced rollers 48, 50. The assembly 14 also includes an upper conveyor 52
formed by a plurality of conveyor belts trained about two spaced rollers
54, 56. The upper conveyor is positioned immediately over the lower
conveyor so that as signatures are fed to the intermediate conveyor
assembly from the upstream folding assembly 12, they are held between and
transported by the conveyors 46, 52.
Additional support is provided to the lower conveyor 46 by a support plate
58 which is connected to the frame and extends between the rollers across
the width of the apparatus. This plate allows the upper conveyor 52 to
apply pressure to the signatures being conveyed so that the signatures are
positively transported along the assembly 14.
It is possible to employ the apparatus in a first mode, wherein once each
signature has been folded within the upstream folding assembly 12, it
by-passes the downstream folding assembly 16 and is delivered from the
apparatus. In order to enable this mode of operation, the apparatus
includes a creel 60 positioned at the downstream end of the intermediate
conveyor assembly 14 for receiving signatures from the conveyor assembly
and depositing them on the delivery conveyor 18. The creel includes a
plurality of protruding, curved fingers within which the signatures are
received as the signatures exit the conveyor assembly, and is rotated in a
clockwise direction, as shown in FIG. 1, so that the signatures are
deposited on the delivery conveyor.
The downstream folding assembly 16 is shown in FIG. 5, and includes a
chopper 62 and a pair of rollers 64. The chopper includes an elongated,
angled body formed by a pair of spaced side walls which are secured
together by a number of cross pieces. A chopper blade 66 formed of a
rectangular flat piece of spring steel or the like is supported at one end
of the chopper 62 and presents an edge extending in a direction parallel
to the direction of travel of the web through the apparatus.
The chopper is supported on a shaft 68 extending along the side wall 22 of
the frame 10 in a direction parallel to the direction of travel of the
web. The chopper may be pivoted about this shaft 68 between a raised
position in which the blade 66 is disposed above the delivery path defined
between the upper and lower conveyors 52, 46 of the intermediate conveyor
assembly 14, and a lowered position in which the chopper blade passes
through the delivery path into the nip defined by the rollers 64.
A drive assembly 70 is connected to the chopper 62 opposite the shaft 68
from the chopper blade 66, and drives the chopper between these positions
during operation of the assembly. As described below, a drive control
means is associated with the drive assembly 70 for enabling and disabling
the downstream folding assembly independent of operation of the upstream
folding assembly. Thus, it is possible to disable the drive to the chopper
in order to allow the production of cross-folded sheets, or to enable the
chopper when chop folding is also desired.
The rollers 64 are supported on the frame beneath the intermediate conveyor
assembly 14, and extend in a direction parallel to the direction of travel
of the web. The support plate 58 supporting the upper run of the lower
conveyor 46 includes a horizontal opening 72, shown in FIG. 2, aligned
with the nip defined by the rollers 64. Returning to FIG. 5, the drive
assembly 70 also drives the rollers 64 via a belt 74 so that the rollers
rotate inward toward one another.
Thus, during a folding operation within the downstream folding assembly 16,
a cross-folded signature positioned beneath the chopper 62 is forced
downward past the lower conveyor 46 by the chopper as the chopper moves to
the lowermost position. The blade 66 forms the fold line in the signature
and pushes the signature into the nip between the rollers 64 so that the
signature is pulled from the conveyor as a fold is formed along the fold
line by the pressure between the two rollers. A creel 76 similar to the
creel 60 is supported on the apparatus beneath the rollers 64, and
includes a plurality of protruding fingers which receive chop-folded
signatures from the rollers 64 and deposits the signatures on the delivery
conveyor 18.
As illustrated in FIG. 3, a head stop 78 is positioned within the delivery
path for limiting the movement of each signature along the path and for
positioning the signatures relative to the downstream folding assembly. In
addition, the apparatus includes an adjustment means for adjusting the
position of the head stop along the delivery path during operation of the
downstream folding assembly so that the position of the head stop may be
adjusted without shutting off the apparatus.
The head stop and adjustment means preferably take the form of a slide
plate assembly 80 which includes a generally rectangular slide plate 82 on
which the head stop 78 and a pair of tail brushes 84 are supported, and an
adjustment mechanism 86 for supporting the plate on the apparatus.
As shown in FIG. 2, the slide plate 82 is substantially flat, having a pair
of lateral extensions which rest on the side walls 20, 22 of the frame
when the side plate assembly is positioned on the apparatus.degree. A pair
of axially aligned slots 88 are formed in the slide plate 82 within each
of these extensions, and removable fasteners 90 are provided which retain
the plate on the side walls of the frame.
The fasteners are illustrated in FIG. 6, and are of conventional
construction, each including an elongated, hollow pin 92 provided with a
transverse hole adjacent the bottom end through which a ball 94 protrudes
to retain the pin on the frame. A release button 96 is provided on each
fastener for releasing the ball into the pin so that the pin may be pulled
from the frame to permit the plate to be lifted or removed from the
apparatus.
Turning to FIG. 5, the slide plate 82 includes a pair of upstanding
L-shaped lugs 98 to which a transverse bar 100 is connected. As
illustrated in FIG. 2, a plurality of holes 102 are formed in the plate
downstream of these lugs 98, and the tail brushes 84 are supported on the
transverse bar and protrude through the holes into the delivery path. The
brushes are adapted to engage each signature as it travels toward the head
stop 78 to prevent the signatures from bouncing from the head stop out of
alignment with the chopper 62.
An elongated, generally rectangular slot 104 is also formed in the plate,
and extends in a direction parallel to the direction of travel of the web.
This slot 104 is adapted to be aligned with the nip rollers 64 so that
during a folding operation by the downstream folding assembly 16, the
chopper is able to pass through the slot. Additional holes 106 are formed
in the slide plate to either side of the elongated slot 104 downstream of
the tail brushes. These holes 106 are spaced from one another by a
distance corresponding to the spacing between belts of the upper and lower
conveyors 46, 52 so that the holes extend through the plate within an area
aligned with the gaps between the belts.
The head stop is also illustrated in FIG. 2, and is formed of a rectangular
piece of steel that is secured to the slide plate 82 by bolt and nut
assemblies 108, 110 positioned at each end of the head stop. A hole is
provided in the head stop through which the assembly 108 is received, and
defines an axis about which the head stop may be pivoted relative to the
plate. The other bolt and nut assembly 110 is received within a slot
formed in the head stop so that, when the nuts of the assemblies 108, 110
are loosened, the head stop may be pivoted relative to the plate. A
threaded adjustment member 112 is supported between the head stop and
slide plate at a position opposite the pivot axis, and is operable to
carry out the pivoting movement of the head stop to adjust the angular
position of the stop relative to the chopper once the slide plate assembly
is in position on the apparatus.
The head stop 78 includes a number of depending legs 114, as shown in FIG.
6, aligned with and extending through the holes 106 in the plate 82. In
addition, the head stop includes a central cut-away region 116 aligned
with the elongated slot 104 in the plate and with the underlying nip
rollers 64. The depending legs 114 on the head stop are sized to extend
beneath the plate 82 into the delivery path defined within the conveyor
assembly to present a head wall against which each signature is forced as
the signature is conveyed through the apparatus. The function of the head
stop is to position each signature beneath the chopper prior to the second
folding operation and to square the signature with the chopper so that the
fold is accurately made.
As shown in FIG. 3, the downstream end of the slide plate 82 is formed with
upstanding side and end walls by which the plate is connected to the
adjustment mechanism 86. Turning to FIG. 6, the adjustment mechanism
includes an elongated shaft 118 attached to the side walls 20, 22 of the
frame, and one end of the shaft protrudes through the side wall 20 to
support a handle by which the shaft may be rotated relative to the frame.
A block 120 of relatively resilient material such as nylon or the like is
mounted on the side wall 20 and includes an opening through which the
shaft extends, the opening being of an adjustable size so that it is
possible to adjust the frictional pressure exerted on the shaft by the
block. The shaft 118 may be rotated by overcoming the frictional force
exerted by the block 120, but the shaft is normally retained in place by
the block so that normal vibration of the apparatus does not upset the
position of the shaft.
An L-shaped lug 122 is secured to the shaft 118 adjacent the inside of each
side wall 20, 22, the lugs depending from the shaft and including a lower
flange to which the slide plate 82 is secured. Preferably, additional
fasteners 90 are employed to retain the plate on the frame. The fasteners
extend into the lugs 122 through vertical slots 124 formed in the side
walls of the plate, as shown in FIG. 4, so that when the shaft is rotated,
the lugs force the plate to slide relative to the frame in a direction
parallel to the direction of web travel.
When the apparatus is to be used in a chop-fold mode, the slide plate
assembly 80 is positioned in the apparatus over the lower run of the upper
conveyor 52 of the intermediate conveyor assembly 14, as shown in FIG. 3,
and the plate 82 is supported on the side walls 20, 22 by the removable
fasteners 90. In addition, the plate is connected to the lugs 122 of the
adjustment mechanism 86 by the additional fasteners 90.
If it is necessary to adjust the angle of the head stop 78 in order to
square the stop relative to the nip defined by the rollers 64, the bolt
and nut assemblies 108, 110 are loosened and the threaded adjustment
member 112 is operated to adjust the angular position of the stop. Once
properly adjusted, the head stop is again secured to the plate by
tightening the nut and bolt assemblies.
Once the slide plate assembly 80 is in position and the downstream folding
assembly has been enabled, as described below, the apparatus is setup for
chop-fold operation. Upon start-up, each cross-folded signature delivered
from the upstream folding assembly is conveyed along the delivery path
until it abuts the head stop 78, which positions the signature relative to
the chopper blade 66 and squares the signature so that it is folded along
the desired fold line.
Thereafter, the chopper 62 is moved into engagement with the signature and
forces it between the rollers 64 so that the rollers may fold the
signature and pull it from the intermediate conveyor assembly 14. The
chop-folded signature is then delivered from the rollers to the creel 76
which deposits the signature on the delivery conveyor 18.
One advantage achieved through the use of the preferred construction of the
present invention is that in addition to supporting the head stop 78 for
adjustment relative to the folding assembly 16, the slide plate also
substantially covers the signatures as they are engaged by the rollers 64
and pulled from the conveyor assembly 14. Normally the signatures would be
free to whip up between the belts of the conveyor assembly 14 as they are
folded. However, the plate prevents such whipping action, preventing the
signatures from being improperly folded across a corner and ensuring that
a high-quality product results.
If, during operation of the apparatus, the signature is engaged by the
chopper before reaching the head stop 78, or if the signature hits the
stop with so much momentum as to possibly damage the signature, the
position of the head stop may be adjusted. The desired position for the
head stop is one in which each signature contacts the head stop with
enough force to square the signature to the chopper but without sufficient
force to damage the signature.
In order to carry out adjustment of the head stop, the operator rotates the
shaft 118 of the adjustment mechanism 86, overcoming the friction force
exerted by the block 120 and pushing or pulling the slide plate 82 and
head stop in either the upstream or downstream direction. For example, if
the signatures are not reaching the head stop before the chop-folding
operation, the shaft 118 is rotated in the counterclockwise direction, as
shown in FIG. 4, so that the lugs push the plate in the upstream
direction. This sliding movement of the plate is allowed and guided by the
removable fasteners 90 extending into the side walls of the frame. Thus,
adjustment of the head stop may be made "on the fly" without shutting the
apparatus down, and further adjustments may be made, if necessary to
obtain the proper alignment of the head stop for various signature sizes,
press speeds and folding configurations.
As mentioned, the upstream folding assembly 12 is provided on a cassette
which is removable from the apparatus to enable replacement of the
cassette and of the assembly. Thus, if the folder apparatus is to be used
with a convertible web-fed press, such as the press marketed by Didde Web
Press Corporation under the name Didde VIP Web Offset Variable Insert
Press, the folder apparatus may also be converted to fold such variable
sized signatures simply by replacing the cassette which supports the
upstream folding assembly.
The cassette is shown removed from the apparatus in FIG. 8, and includes a
gear train supported outside one of the side walls 30 for driving the
tucker and gripper cylinders 24, 26, as well as the conveyor 28. The gears
126, 128 associated with the tucker and gripper cylinders are sized
proportionally to the size of the cylinders so that operation of the
upstream folding assembly may be coordinated with operation of the
downstream folding assembly regardless of the size of the cylinders 24,
26. For example, a cassette supporting a folding assembly for use with
relatively large signatures is shown in FIG. 9, and includes gears 126',
128' which are oversized relative to the gears 126, 128 of the cassette
shown in FIGS. 1 and 8.
In order to permit the upstream folding assembly to be replaced with
variable sized cylinders, and to allow the downstream folding assembly to
be enabled and disabled when desired, the apparatus is provided with a
unique drive system including a registration means for registering the two
folding assemblies 12, 16 with each other so that after the cassette is
replaced or the downstream folding assembly is enabled, the two assemblies
may be registered with one another.
This drive system is shown in FIG. 1, and broadly includes an input drive
assembly 130, the gears 126, 128 forming the train for the upstream
folding assembly 12, a transmission assembly 132, and the drive assembly
70 for the downstream folding assembly 16.
The input drive assembly 130 includes a rotating shaft 134 which transmits
drive to the apparatus from the upstream printing press. This drive is
transmitted through a gear box and a belt-and-pulley arrangement to a
drive gear 136. The belt-and-pulley arrangement also provides drive
through a belt 138 to the upper and lower conveyors 46, 52 of the
intermediate conveyor assembly so that the conveyors operate whenever the
upstream folding assembly is operated.
A swing arm 140 is supported on the axis of the drive gear 136 for pivotal
movement about the axis, and a swing gear 142 is mounted for rotation on
the swing arm and engages the drive gear. When the swing arm is pivoted in
the counterclockwise direction, as shown in FIG. 1, the swing gear 142 is
moved into engagement with the tucker gear 126 and drives the upstream
folding assembly. However, the swing gear may be disengaged from the
tucker gear by pivoting the swing arm in the opposite direction.
A small gear 144 is attached to the gripper gear for rotation with the
gripper gear, and engages the transmission assembly for transmitting drive
to the downstream folding assembly. The transmission assembly 132 includes
a gear train connect | | |
