Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
FIELD OF THE INVENTION.
The present invention relates to a folding apparatus,
and more particularly to a folding apparatus using a folding
cylinder in which a folding or tucking blade pushes web products,
particularly printed products received from the printing
machine into folding jaws of an associated folding jaw cylinder;
and especially to such an apparatus in which the tucking blade
cylinder has a needling system to retain the ~Linted products
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thereon, and which is so arranged that paper jams or stoppers
will not damage the apparatus or interfere with the printing
machine as a whole.
Background.
The referenced literature, "Atlas des Zeitungs- und
Illustrationsdruckes" ("Atlas of Newspaper and Magazine Printing")
by Alexander Braun, published by Polygraphverlag, 1960, page 69,
describes a folding apparatus of the type in which a combination
folding blade or tucking blade - product gripping cylinder is
associated with the folding jaw cylinder; and on which the
combination folding blade - product gripping cylinder further
has, on the circumference thereof, cutter counter elements, so
that the folding blade cylinder can, also, cooperate with a
rotating cutter knife cylinder. The foregoing literature also
discusses, see page 75 thereof, that such folding apparatus
may be subject to damage if a paper jam or stopper occurs. This
danger is particularly acute for control apparatus therefor.
It has been proposed to utilize automatically operating
safety clutches, coupled in the drive for the folding apparatus,
so that the folding cylinder set or group can be disconnected
at the same time that the drive motor for the machine is stopped.
Stoppers or paper jams, or other accumulationsof paper can
occur especially between a folding jaw cylinder and a
folding blade or tucking blade cylinder if the folding blade or
tucking cylinder, for the gripping function of the printed
products, uses needles or the like. It may occur that the
already cut sheets, which are on the combination foldlng blade -
gripping element cylinder - can slip off the needles thereof~
which carry out the gripping function. A cut sheet, which
leaves the circumference of the cylinder, and loses contact
with the folding blade cylinder, can then be carried along by
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the subsequent sheet, which will lead to a jam, that is, an
accumulation of paper in the nip between the folding jaw cylinder
and the combination folding blade - needling cylinder. Such a
paper jam or paper accumulation may lead to damage in the
system. Similar problems can occur if the end portion of a cut
sheet folds itself over.
It has been proposed to eliminate danger and damage to
equipment upon occurrence of stoppers or paper jaws to locate
one of the cylinders such that it can be moved away, for example
pivoted away, thereby increasing the nip or gap width between
the combination folding blade - needle cylinder and the folding
jaw cyllnder, to obtain a gap which is sufficiently wide to pass
accumulated pa?er. Supervision of the folding process, and
moving away one cylinder from the other, is expensive. Further,
the response time of such a system is unduly long.
THE INVENTION.
It is an object to provide a folding system in which
the consequences of stoppers, paper jams or paper accumulations
are effectively avoided, and which is simple and inexpensive.
Briefly, passage of accumulated or incorrectly fed
paper between adjacent folding jaw cylinders and combination
folding or tucking blade - sheet gripping cylinders is facilitated
by forming recesses or grooves or flattened surfaces extending
axially on the folding jaw cylinders, and so positioned that,
when a counter cutting element is in the position of the nip,
i.e. opposite the folding jaw cylinder, the recess groove or the
like is immediately opposite the counter knife element.
The grooves, recesses, or flattened portions on the
folding jaw cylinder can be covered by elastic elements, for
example strips of spring steel, or a suitable elastic plastic.
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The elastic elements, under normal operation, are so arranged
that they complete the circumferential outline of the folding
~aw cylinder. A plurality of ad~acently located elements of
this type can be used.
The system has the advantage that the cylinders need
not be shifted; yet, dangerous conditions which may arise
due to a paper jam, stopper or other accumulation of paper in
the nip between the cylinders is effectively eliminated. If
there is an accumulation of paper, a jam or the like, the
grooves or flattened surfaces on the folding jaw cylinder
located between the folding jaws thereof, lead to a resiliently
yielding increase in the width or gap dimension of the nip.
The circumferential dimension of the combination folding blade -
gripper system cylinder is unyielding at the
circumferential position of the knife counter element since, as
noted, this cylinder is designed to cooperate with a cutting
knife cylinder. The presence of the groove, however, permits
accumulated paper to pass through this nip. Any cover of the
groove, for example by elastic material or spring steel, permits
yielding deflection towards the root or base of the groove
so that accumulated paper can readily pass through the nip
without damage to the system.
Combination folding blade - needle cylinders usually
are so arranged that the diameter thereof can be adjusted.
The diametrical dimension adjustment system may be controlled
by eccentrically journalled bolts or the like. These segments,
in case of a paper accumulation thus can yieldingly deflect
towards a smaller diametrical dimension. In the region of the
knife counter elements~ however, the circumferential design
dimension must be maintalned, and stable construction of the
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cylinder is necessary. The knife counter element or a groove
defining strip or rod may form the knife counter element itself,
or a support bar strip or rod for the knife counter element,
so that the cutting knife of a cooperating cylinder can cut a
continuous web into sheets. Since the region of the knife counter
element, or such a groove or support rod or bar,is always ~n the
region between two folding jaws of a folding jaw cylinder, as the
cylinders roll off against each other, the problem of paper
accumulation or stoppers can be readily solved by relieving a
portion of the circumference of the folding jaw cylinder between
the folding jaws themselves, that is, by forming the above
described recess or groove.
DRAWINGS:
Fig. 1 is a highly schematic side view of a folding
system in accordance with the present invention, in which a
continuous web is first cut into sheets which are then
folded;
Fig. 2 is an enlarged detailed view of a portion of a
combination folding or tucking blade - needle cylinder, and
illustrating the region of a cutting groove - knife counter
element;
Fig. 3 is a fragmentary axial cross-sectional view of
a folding jaw cylinder, illustrating the present invention; and
Fig. 4 is a view similar to Fig. 3, and illustrating
another embodiment.
DETAILED DESCRIPTION.
A continuous web 2, for example derived from a
printing machine, is guided to the folding system 1, by being drawn
over pull rollers 3, 4 which, for example, may be constructed in
accordance with the referenced Patent 4,748,910, Richter.
The web 2 then is passed between a cutting knife cylinder S and
a combination folding blade - needle cylinder 6. The cutting
knife cylinder 5 has two oppositely located cutting knives 7.
The combination folding blade - needle cylinder 6 is formed
with a plurality of counter cutting grooves 8 and needles 9.
Rather than using the needles 9, grippers can be used.
These needles 9 or grippers, respectively, which may be collectively
referred to as sheet gripping means, are provided to hold the
leading portion of the web 2 before a knife 7 cuts the web,
in cooperation with the counter cutting strip 8. The cut portions -
not specifically shown in Fig. 1 to simplify the drawing - are
then guided by the grippi-ng structure about the circumference of
the combination folding blade - needle cylinder 6. A folding
or tucking blade 10 is projected from the combination cylinder
at an appropriate moment to insert the crease formed thereby into
the jaws 13, 13' of an associated neighboring folding jaw
cylinder 12. The thus folded products are then delivered to a
paddle wheel distributor 14, being guided thereto in a direction
of the arrow 15. The paddle wheel distributor 14 then
distributes the folded products on a suitable transport belt
system 16, shown only schematically.
The apparatus so far described can be conventional
and can be conctructed in accordance with conventional cylinders
and arrangements.
It may occur that in the region of the nip A between
the combination cylinder 6 and the folding jaw cylinder 12
- a paper jam or paper accumulation or a stopper may occur which,
unless remedied, may lead to damage of either one or both of the
cylinders 6, 12, if the thickness of printed su'- ect matter
passing between the cylinders 6, 12 is excessive. Customarily,
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a diameter adjustment system generally shown at 17 permits
an increase of the gap width of the nip between the cylinders 6,
12 and in the region where the diameter adjustment is effective,
the consequences of a paper accumulation may not be serious.
In the region of the counter knife element strips 8,
supported by suitable groove support or groove wall rods or
rails 11 (Fig. 2), the diametrical dimension of the cylinder 6
cannot be adjusted. Thus, an increase of the gap width between
the cylinders 6, 12,at the critical point where the hard,
unyielding counter knife 8 or its support bar 11 is located,
no increase of the width of the gap is possible, since neither
the counter knife elements 8 nor the groove support rails 11
can be constructed to be yielding due to the function which
they have to carry out - namely to form a counter cutting surface
lS for the knives 7 of the cutting knife cylinder 6. Thus, the
danger exists that, as an accumulation of paper tries to pass
between the cylinders 6, 12 at an instant of time when the
cutting strips 8,or the groove rails 11, respectively, pass
through the nip, the portions of the folding system 1 Qan be
damaged or destroyed.
In accordance with the present invention, the region
of the folding jaw cylinder 12,which would be opposite the
counter cutting grooves or groove rails 11, respectively,
which is the region between adjacent folding jaws 13, is
relieved to form a groove or recess 18 (Figs. 1-4) or a flattened
surface 20 (Fig. 3). Thus, when the cylinders 6, 12 roll off
against each other, the reces~es in the cylinder 12, that is,
the grooves 18 or the flattened surfaces 20, will be located
to be opposite the counter knife element 8 and/or the groove
support rail 11, so that the nip between the cylinders 6, 12,
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at that instant of time, is increased, thereby permitt~ng
passage of accumulated paper or the like between the cylinders
6, 12, without danger to the cylinders or to the machlne.
It may be desirable to maintain the cylindrical
contour of the folding jaw cylinder 12. If so, the recess 18,
or the flattened surface 20, can be covered by an elastic covering.
Fig. 3 illustrates, highly schematically, the contour of an
elastic cover 21, which may be formed of adjacently positioned
elements, in which in Fig. 3 the end portion of the element is
visible. Since this is not necessary, however, the contour has
been shown in chain-dotted lines. Rather than using an elastomer
materlal, placed in segments, for example, a circumferential
cover of spring strip steel 19 (Fig. 4) can be placed to cover
the groove 18 or, respectively, the flattened region 20. These
elastic elements 19, 21, respectively, bridge the recess formed
by the groove 18 or the flattened surface 20.
- The elements 13, 19, as well as the recess 18~ have
; been supplied with reference numerals in Fig. 1 only once
to retain the clarity of the drawing.
The length of the recesses 18, 20, respectively, in
circumferential direction of the folding jaw cylinder can be
easily determined by computation or experiments. Usually, the
longest possible circumferential portion between two adjacent
folding ~aws 13 should be recessed to form the respective grooves
or flattened surfaces. Fig. 4 illustrates a suitable arrangement
in which the length of the recess formed by the groove 18 is
a maximum. The longer this groove or flattened regions
can be made, the better the assurance that in case of a
stopper, paper jam or paper accumulation, such accumulated
extra thickness material can pass through the nip between the
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cylinders 6 and 12, without danger of damage, in spite of the
fact that the diametrical position of the counter cutting
element 8, or the groove support rail 11 is diametrically fixed.
Various changes and modifications may be made, and
any features described herein with respect to any one embodiment
may be used with any other feature, or embodiment, within the
scope of the inventive concept.
