Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD AND APPARATUS FOR DELIVERING FLAT ARTICLES TO A
GENERALLY VERTICAL HOPPER
[0001] The present invention relates to methods and apparatus for
delivering flat products such as printed sheet signatures ("signatures") to a
generally vertical hopper pocket. More specifically, the invention relates to
a method and apparatus for transferring and separating a vertically
aligned, parallelepided shaped stack of on-edge signatures to
continuously load a generally vertical hopper pocket of a machine
performing feeding of bindery equipment such as stapling and stitching
equipment which process signatures on a one-at-a-time basis for the
manufacture of books, magazine or the like. Although the present invention
will be described by reference to handling of signatures in a bindery
process, it shall be deemed applicable to a variety of applications dealing
with flat products in flexible sheet form.
(0002] Traditionally, the loading of bindery line systems, generally
comprising a hopper and a rotary feeding drum, was manually
accomplished by an attendant. When the signatures are coming from the
folding operation, they are tightly compressed to form a bundle and some
of them frequently adhere to each other depending on various printing and
storage conditions. It is well known in the field that the reliability and
through-output of the bindery line is mainly lying on the ability to properly
operate signature separation, as traditionally executed by the attendant, so
that the feeding system will continuously succeed at transferring one
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signature at a time to the gathering conveyer, thus avoiding costly
interruptions of the bindery line. The manual operation of separation is
usually carried-out by the attendant by taking a pile of signatures and
bending the pile back and forth a few times. Additionally, some tapping of
the edges of the pile on a generally horizontal flat surface may be
perFormed. Also, the attendant carefully controls manual loading to prevent
causing excessive load which may prevent the feeder from successfully
pulling the leading signature. While automatic hopper loaders are now
currently in use to accomplish the task of Loading the hopper pocket of
feeding systems, a main challenge still resides in performing proper control
of hopper loading in order to prevent misfeeds and malfunctions, leading to
costly process interruptions and operator interventions.
[0003j Indeed, a critical aspect for ensuring proper operation of a
bindery equipment feeder is proper upstream separation of the signatures
and proper control of the pressure on the back plate of the hopper pocket.
Too much pressure as caused by excessive thickness of the signature
stack or brutal changes thereof increases the risks of misfeeds and
interruptions. It is consequently of prime importance to maintain pressure
and friction force within specific operational limits in order to ensure
proper
operation of the system feeder. White a minimum stack thickness will help
maintaining the bottom signature in close contact with the back plate, a
stack of excessive thickness will cause too much friction force to be
developed on the leading signature, which will overcome drag force from
the feeder and prevent proper feed. Similarly, suddenly dropping too many
signatures within a short period of time into the hopper will generate an
impact force with equivalent effects.
[0004] Some signature loaders performing delivery of signatures, from
tightly packed vertically aligned, parallelepipeded shaped stacks (bundles
or togs) to generally vertical hopper pockets are already known in the prior
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art. For instance, the apparatus described in US patent 6,017,029, granted
to Bates et al. on January 25, 2000, is a movable hopper loader wherein
signatures are separated by three conveyors, the downstream conveyor
performing direct continuous loading of the pocket. A top jogger is
provided to align signatures in the pocket. Such a structure proved to be
inefficient for several reasons. Firstly, the original conveyor at the bottom
of the feeder's hopper must be modified or removed to enable coupling of
the loader. Also, continuous loading of the signatures prevent proper
control of stack thickness and friction in the pocket. Jogging efficiency is
also impaired due to excessive friction between signatures and to the fact
that the top edge of the folded signatures standing on their backbone
(spine) does not offer sufficient rigidity to transfer the motion and energy
from the jogger to push signatures down, said top edge simply giving and
bending uselessly. Many other loaders of older generations present similar
limitations and drawbacks in addition to limited or impossible mobility from
a piece of bindery equipment to another. US patents No 5,374,050 (Prim -
Dec. 20, 1994), 4,973,038 (Curley et al. - Nov. 27, 1990), 4,180,259
(Bewersdort et al. - Dec. 25, 1979) and 4,177,982 (Bewersdorf et al. -
Dec. 25, 1979) represent examples of such signature bundle loading
equipment.
[0005] Hopper-loaders based on a different concept have also been
taught in an attempt to solve some of the above limitations and drawbacks.
For example, Bates, in US patent application No 2004/0245716 A1
(Published on Dec. 9, 2004), discloses an attachment for converting a
horizontally oriented stack of signature from a loader to a vertically
oriented stack in a hopper pocket. This concept is quite similar to that of
the adaptor patented by Chandhoke on March 13, 1984 under US patent
No 4,436,297.
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[0006] These concepts avoid modifications of the bindery equipment
feeder by dropping signatures from the top directly on the e~asting chain
conveyor of the hopper pocket. When such attachments are mounted at
the output of a typical loader, a bundle of signatures is separated to form
an overlapping shingled stream of signatures which are then accumulated
into an intermediate horizontal pocket. These signatures are then fed one
at a time or in thin overlapping shingle form from the intermediate
horizontally oriented stack to the feeder's vertical pocket, which may
provide good control of stack thickness, pressure and friction in that
pocket. However, creating an intermediate horizontal stack and providing a
vacuum stripper belt conveyor to pull signatures from the bottom of the
stack adds much complexity to the equipment. This increases the
probability of jam, misfeed and malfunction during operation, in addition to
requiring more extensive set-up according to paper dimension and weight.
Furthermore, these complicated structures add to the construction and
maintenance costs of the equipment.
[0007] By observing these concepts, one may notice that creating such
intermediate stacks actually serves to convert the incoming shingled
stream wherein the leading signature lies at the bottom of the stream into
an inverted shingled stream wherein said leading signature lies free on the
top thereof, in a convenient position enabling it to be dropped from the top
in a vertical pocket. Indeed, experience has shown that directly creating an
inverted shingle between the loading bed and the second conveyor of a
loader causes an unstable behavior yielding low reliability and calling for
considerable operator attention.
[0008) The above review of the prior art clearly shows that no
reasonably reliable and practical solution exists to solve the problem of
loading a generally vertical hopper pocket with signatures standing on
their backbone. Therefore, the present invention aims at providing a .J
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stream inverting loader for the loading of vertical hopper pockets, wherein
no intermediate pocket for accumulating a vertical stack of horizontally
oriented signatures is implemented.
(0009] An object of the present invention is therefore to provide a
method and an apparatus for loading flat articles into a generally vertical
bindery equipment hopper pocket while obviating the limitations and
drawbacks of the prior art systems. Contemplated benefits of the present
invention include:
(0010] avoiding modifications to the feeder's hopper pocket and
conveyor;
(0011) enabling loader mobility from a piece of bindery equipment to
another;
(0012] providing a high level of signature separation,
(0013] providing precise control of the stack thickness, alignment and
pressure, into the vertical hopper; and
(0014] preserving the physical integrity of signature edges.
(0015] More specifically, in accordance with the present invention,
there is provided an apparatus for automatically loading flat articles into a
generally vertical hopper pocket of a feeding machine, said apparatu
r,_
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comprising: a first conveyor; an adjacent upstream second conveyor
adapted to run faster than said first conveyor and upwardly inclined with
respect thereto; a third conveyor adjacent and upstream said second
conveyor, driven independently from said first and second conveyors and
having an outlet end adapted to deliver signatures substantially vertically
into the pocket; a first sensor for generating a signal indicative of the
presence of flat articles at a downstream end of said second conveyor; a
second sensor for generating a signal indicative of a thickness of articles
in the pocket; and a controller for receiving signals from said first and
second sensors and for controlling said first and second conveyors
according to said signals, whereby flat articles can be transferred to the
pocket one small packet at a time.
[0016] There is further provided an apparatus for automatically loading
flat articles into a generally vertical hopper pocket of a feeding machine,
further comprising a jogger assembly adapted to jog lower and side edges
of articles in said pocket so to promote separation and alignment thereof.
(0017] There is further provided a method for automatically loading flat
articles into a generally vertical hopper pocket of a feeding machine, said
method comprising:
a) loading and conveying at a first speed a vertically aligned,
parallelepipeded shaped stack of signatures on an in-feed conveyor,
with the backbone edge facing upward;
b) transferring signatures to a second conveyor, running faster than
said first conveyor and upwardly inclined with respect thereto, to
create on said second conveyor a continuous overlapping shingled
stream of signatures having their backbone edge on top and facing
downstream.
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c) transferring a downstream portion of said shingled stream of
signatures on a third conveyor in order to separate said portion from
the continuous stream to define a shingled packet of signatures;
d) conveying said packet of signatures into the generally vertical
hopper pocket with the backbone edges facing downward, using said
third conveyor; and
e) jogging lower (backbone) and side edges of signatures into said
hopper pocket to form a stack of aligned vertically oriented signatures.
[0018] FIG. 1 is a side elevational schematic view of a preferred
embodiment of the apparatus of the present invention, loading a generally
vertical hopper pocket of a signature feeding equipment.
[0019] FIG.2 is an enlarged side elevational schematic view of the
downstream end of the apparatus of FIG. 1, showing details of the inverting
mechanism thereof.
[0020] FIG. 3 shows a schematic diagram of the operating protocol
carried-out by the apparatus of Figure 1 according to an embodiment of the
present invention.
[0021] FIG. 4 shows a schematic representation of the flat article loading
method according to the present invention.
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[0022) A preferred embodiment of the method and flat article delivering
apparatus of the present invention will now be described in detail referring
to
the appended drawings.
(0023) Referring to FIG.1, there is provided an apparatus generally
identified by numeral 1, which is designed to deliver incoming bundled
signatures B standing upright on edge to a hopper 101 of the feeding
system 100 of a bindery line as a generally vertically oriented stack SVS.
The bottom of hopper 101 is constituted by a chain feed conveyor 102.
[0024) Apparatus 1 comprises a mobile frame 2 supporting a loading
bed including a first substantially horizontal in-feed conveyor 3, preferably
made of four steel flat chains, driven at a first linear speed in direction F.
Bundles B of signatures S can be loaded on conveyor 3 and have their
straps and end plates removed in order to free signatures S to be
conveyed and separated from each other. A second rising belt or chain
conveyor 4 driven at a second speed higher than said first speed extends
adjacent or slightly overlapping a downstream end 3b of conveyor 3.
Conveyors are driven by gear-motors and clutches under control of
controller 5 connected to an operator control panel (not shown). That
conventional structure is well known by those of ordinary skill in the art of
bindery hopper-loaders. Signatures S are thereby separated to form an
overlapping shingled stream SS on conveyor 4 comprising an upwardly
inclined upstream portion 4a and a substantially horizontal downstream
portion. 4b, that sudden change in angular orientation further promoting
signature separation.
,y
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(0025] Improvements in apparatus 1 consist in the feed module 20
downstream conveyor 4 and can be better seen from the enlarged view
illustrated at FIG. 2. Module 20 can be implemented as an integral portion of
apparatus 1 or can be manufactured as an add-on attachment adaptable to an
existing conventional hopper-loader A sensor 6 of any suitable type detects
the presence or absence of signatures at the downstream end 4b of conveyor
4 and sends a status signal to controller 5. A third conveyor 7, preferably
comprising three parallel belts 8, is adjacent to and extends downstream from
the downstream end 4b of second conveyor 4. Conveyor 7 further includes an
upper section comprising three "O ring" belts 9 running on top of each one of
the three belts 8 of conveyor 7. Thereby, signatures S carried in conveyor 7
are properly guided between and in Gose contact with upper and lower sets of
belts 8, 9 to be accurately directed along the arcuate outlet portion 10
providing a change in direction of approximately 90 degrees to outlet 11 thus
delivering signatures with a substantially vertical orientation into hopper
101.
Outlet portion 10 can be pivoted up and down about axis 14 to set outlet 11 to
an appropriate height with respect to hopper conveyor 102 according to the
length of the signatures S to be fed.
(0026] A critical aspect of the present invention is that signature stream
SS can not be continuously directed to hopper pocket 101 since the leading
signature lies at the bottom of the overlapping shingle. Therefore, an
inventive
inverting operating mechanism is implemented in teed module 20. Conveyor 7
is continuously running during normal operation of apparatus 1 and sensor 12
generates a signal responsive to the presence or absence of signatures in
conveyor 7. Further, another sensor 13, generates a signal representative of
the thickness of the vertical signature stack SVS in hopper 101, both signals
being sent to controller 5. The corresponding operating protocol is
schematically represented in FIG. 3 and works as follows:
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(0027] If sensor 6 does not detect signatures, controller 5 runs conveyors
3 and 4 until the signature stream reaches said sensor and then stops,
thereby ensuring continuous availability of signature supply at the downstream
end of conveyor 4. Then, controller 5 monitors the signal from sensor 13 to
determine if the thickness of the signature stack in hopper pocket 101 is
within
operational limits - if thickness is less than a user set value (typically 4
to 6
inches according to paper density to thereby prevent excessive pressure and
friction to be developed between signatures and at the back-plate and avoid
misfeeds) controller 5 monitors the status of sensor 12. Else, it returns to
monitoring of sensor 6. If the signal from sensor 12 indicates that conveyor 7
is empty, the controller activates conveyors 3 and 4 for a short period of
time
Ot (typically 0.3 second) to enable a definite length of shingled signatures
(single separated packet) to pass from conveyor 4 to conveyor 7 and be
directed into hopper 101. The operation is continuously repeated thus loading
small packets of shingled signatures one after the other to gently keep the
supply of signatures SVS within safe operational limits, as an attendant would
do manually.
(0028] It shall be noted that signatures in the packets deposited onto
conveyor 102 of hopper 101 being constituted from separated shingle portions
are vertically shifted relatively to each other when dropped. It is therefore
advisable to provide feed module 10 with a vertical jogger 15 comprised of
vertically oscillating plates extending upwardly between the chains of
conveyor 102 to contact the lower edge (backbone) and vibrate the signatures
to align them all in contact with conveyor 102 downstream the jogger plates.
Jogger plates 15 are slightly more tilted than conveyor 102 in the downstream
direction to help signatures slip in the downstream direction. Plates 15
further
comprise an angular stop kick upstream the drop zone to prevent dropped
signatures from moving in the upstream direction and provide additional bias
in the downstream direction at this critical zone. Jogger 15 is driven by
electrical gear-motor assembly 17 through linkage 18 simultaneously driving a
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second set of two symmetrical lateral jogging arms 19 {one shown). Arms 19
jog the sides of vertical signature stack SVS to ensure proper lateral
alignment
thereof.
(0029] In operation, a bundle of vertically aligned, paraileiepipeded
shaped stack (bundle) of signatures B is loaded on the upstream portion 3a of
in-feed conveyor 3 with the backbone edges facing upward. The straps and
end plates of the downstream bundle are removed to release the signatures S
retained between the new bundle and the downstream signatures. The free
signatures are conveyed on in-feed conveyor 3, up to upwardly inclined belt
conveyor 4, whereat the changes in speed and vertical inclination induce
signature separation and formation of an overlapping shingled stream rising
on conveyor 4 and stopping at the downstream end 4b thereof, below sensor
12, while conveyor 7 is continuously running. Signatures in the stream have
their backbone edge oriented in the downstream direction and the leading
signature is at the bottom, being partly covered by upstream signatures.
[0030] As explained above, controller 5 then periodically activates
conveyors 3 and 4, always running simultaneously, for short periods of time to
deliver individual packets of shingled signatures being pulled out by conveyor
7 and dropped onto jogger plates 15 in hopper pocket 101. Jogged signatures
can then be advanced by conveyor 102 and pulled one at a time by the
bindery equipment feeder 100, at the back-plate of hopper pocket 101. It shall
be noted that vertical jogging is performed on the backbone edge of
signatures to prevent damaging edges and provide optimal strength to transfer
jogging impulses into signatures and impart movement thereto to pertorm final
separation and alignment.
. ,,,
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[0031 The method for delivering flat articles to a generally vertical
hopper pocket according to the present invention is illustrated in FIG. 4.
The method comprises the following steps:
a) loading and conveying at a first speed a vertically aligned,
para((elepipeded shaped stack of signatures on an in-feed conveyor,
with the backbone edge facing upward;
b) transferring signatures to a second conveyor, running faster than
said first conveyor and upwardly inclined with respect thereto, to
create on said second conveyor a continuous overlapping shingled
stream of signatures having their backbone edge on top and facing
downstream.
c) transferring a downstream portion of said shingled stream of
signatures on a third conveyor in order to separate said portion from
the continuous stream to define a shingled packet of signatures;
d) conveying said packet of signatures into the vertical hopper pocket
with the backbone edges facing downward, using said third conveyor;
and
e) jogging lower (backbone) and side edges of signatures into said
hopper pocket to form a stack of aligned vertically oriented signatures.
[0032] Separating the signatures to load a vertical hopper pocket using
simple, reliable and cost-effective structure and method while preserving
their physical integrity achieves a first goal toward increasing the overall
reliability and throughoutput of a signature feeding system. A second goal
toward this objective is accomplished by providing precise control of the
thickness of the stack of signatures SVS in hopper pocket 101.
Furthermore, apparatus 1 is totally independent from feeder 100, can
operate without requiring any modification thereof and can be easily
moved from a feeder to another. t,
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[0033) One can thus easily contemplate that the above described
embodiments of the method and apparatus for delivering flat articles to a
generally vertical hopper according to the present invention obviate the
limitations and drawbacks of the prior art devices.
[0034) Although the present invention has been described by means of
preferred embodiments thereof, it is contemplated that various modifications
may be made thereto without departing from the spirit and scope of the
present invention. Namely, it is obvious that equivalent benefits could be
obtained by replacing the printed signatures referred to in the description by
any other type of generally flat artide in fle~able sheet form. Accordingly,
it is
intended that the embodiments described be considered only as illustrative of
the present invention and that the scope thereof should not be limited thereto
but be determined by reference to the claims hereinafter provided and their
equivalents.
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Inventor
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