Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
BACKGROUND OF TIE INVENT ION
l Field of the Invention
The invention is directed to machinery for slowing down
cut sheets of paper as they are fed to a stacking station and removal
of reams from the stacking station and , more particularly, relates to
a slowdown mechanism avoiding conventional overlap and in which more
than one ream is collected in a pile prior to removal of the reams.
2. The Prior Art
_ _ _
In the paper-cutting machinery field, it is kern for
cut sheets to be overlapped or shingled enroot to a stacking or
collection station. A problem in high-speed sheeting is to be able
to slowdown the sheet sufficiently enough, so as Jo not have lead
edge damage, To do so one necessitates overlapping the sheets where,
again, as one goes up in speed, a limit is reached when the overlap
approaches 100% and the maximum overlap speed reaches 250-350 fpm.
Lowe speed also causes a problem of air in the stacking pile and jog,
making handling of the reams difficult and high quill hard to achieve.
The overlapping or shingling operation is usually performed
by high and low-speed tape systems. The speed of the leading sheet is
reduced as it is fed to the low-speed tape by some suitable means, such
as a stop roll. One example of this stop roll shingling process is
illustrated in ITS Pun No. 3,554,534, where a snooped roll is also
disposed upstream of the stop roll Jo defect the tail ends ox sheets
passing into tune lisped tape down and out of the way of the next
oncoming sheet being delivered by the high speed tape system.
--1--
I
SEYMOUR OF THE_INVE~TION
In this invention, the conventional overlap is eliminated.
Instead of stopping the sheet wit the lewd edge, a tail-stopping device,
consisting in a first embodiment of a top brush roll which knocks the
tail down, allowing the next sheet to cross over and overlap. The
brush roll contacts the sheet near the jail, forcing it down against
a roll going 250-350 pi As the brush leaves the roll, there is
nothing to drive the sheet into the stacking pile, so it sits on the
roll until the brush comes around again, knocking the tail down of the
next sheet. The brush then puts pressure on both sheets. The bottom
sheet is then accelerated to a 150-250 fpm speed into the stacking pile,
while the top sheet then sits on the unzipped, slow-speed roll waiting
for the next nip.
In accordance with a second embodiment/ a stationary air blow-
down is positioned above a slow speed rotating vacuum roll which kowtow
the tail of the sheet. In a third embodiment, the tail of the sheet is
forced down against the bottom roll by an oscillating ~pring-loaded nip
wheel which is actuated by a signal which determirles location of the
sheet edge and gyp in order to maintain its proper position on a trailing
edge of the sheet.
With the second and third embodlmen~s of the invention, the
device includes a rubber-co~ered or h~gh-frietioned bottom vacuum or
plain nip roll which is turning at speed of 250-350 fpm. The fact that
this roll it ~urnlng not only slows down the sheet when it is nipped
against this roll, but also precludes the common problem of sheets
hanging up in this area and not getting into the pile.
ore ken one ream is collected in this tacking, which
accomplishes the compaction needed to compress all the air out of the
pile. The ream aye removed from the bottom of the pile by inserting a
rem splitter spear type of device, whereby at a certain ream thickness,
the spears (with a belt on them are inserted into the pile. Attached
to the pyre pusher which will push thy finished reams from two
I
I
ruling, lift-mounted conveyors onto an air table for conveying
from the machine. In an alternate embodiment of the invention, the
stacker and air table may be disposed at an incline.
BRIEF DESCRIPTION OF THE DRAWINGS
, _ . ... . . _ , . . ..
FIG. 1 is a schematic side elevation Al view illustrating
the slowdown device and ream removal device of the present invention.
FIG. 2 is a schematic side elevation Al view illustrating
an alternative embodiment of the present invention.
FIG. 3 is a partial schematic side elevation Al view ill-
striating a second embodiment of the slowdown device of the present
invention.
FIG. 4 is a partial schematic side elevation Al view ill-
striating a third embodiment of the slowdown device of the present
invention.
FIG. 5 is a partial schematic side elevation Al view ill-
striating a fourth embodiment of the slowdown device of the present
invention.
DESCRIPTION OF TOE P~EFE~R~D EMBODIMENTS
With reference to FIG 1, there is illustrated a series of
sheets, such as paper sheets 10, 12, it and 16 which have been cut by
a knife into individual sheets upstream of FIG. 1 and are being passed
in a seriatim flow. A high-speed tape conveyor system 18 having a tape
means 20 supported at one end by a roll 22 and at the other end by a
similar roll no shown, serves Jo convey the cut sheets at high speed.
The high-speed tape 20 conveys the Sheets a speeds of up to 1500 feet
per minute.
Immediately downstream of the turnaround roll 22, there is
provided a slowdown device in accordance with the presuppose of the
present invention, In the embodiment shown in FIG. 1, there is provided
a tall-~opping device why h comprises a top brush roll 24 and a slowly
--3--
rotating roll 26. Roth rolls 24 and 26 are operated by means of an
electric motor I operating through appropriate gearing means 30.
The slow rotating roll 26 rotates with a surface speed of
approximately 250~350 fpm. The brush roll has two radially extending
brush members 32, 34 which are diametrically opposed on the roll 24.
As sheets are fed by the conveyor system 18, the lead edge of the sheets
passes between the two rolls 24, 26 when the brush members 32, 34 are
disposed approximately horizontally such that the lead edge can pass
between the two rolls. As the sheet continues to pass between the two
rolls, one of the brush members comes in contact with a portion of the
sheet near the tail end and forces the sheet downwardly against the
slowly rotating roll 26. As the brush member, which continues to rotate,
leaves the roll 26, there is nothing to drive the sheet into the stacking
pile, so it sits there until the brush comes around again, knocking the
tail down of the next sheet. us that occurs, the brush memo r puts
pressure on both sheets. In FIG. 1 it is seen that the brush member 32
is knocking down the tail end of sheet 10 wile sheet 12 is still engaged
with the slowdown roll 26. With the brush member puking pressure on
both sheets, the bottom sheet 12 is accelerated to a speed of approximate-
lye 150-250 fpm into the stacking pile as is shown by sheet 14. The top
sheet 10 continues to sit on the unnipped-slow-speed roll 26, waiting
for the next nip of the brush member. In this manner, delivery into the
stacking pile at slow speed is accomplished.
More than one ream of paper sheets is collected in the stacking
pile 36, which accomplishes the compaction needed Jo compress all of the
air out of the pile. The reams are removed from the bottom of the pile
as seen in JIG. 1 where a rem I it being removed, A ream splitter
spear 40 having a sharp pointed leading edge 42 fur original entry into
the sleeking pile 36 and having a belt 44 on the spear is inserted into
the stacking pile 36. The pointed leading edge separates a top sheet 46
Lo
of the lam I from a bottom sheet 48 of the stacking pile 36. The
belt 44 on the spear 40 is supported one end by a front roller 50
and at a secorld end by a rear roller 52. As the spear is inserted into
the stacking pile I separating the roam I from the rest of the pile,
the belt 44 moves on the rolls 50, 52 in a clockwise direction as viewed
in FIG. 1 such that any portion of the belt 44 coming into contact with
the bottom sweet 48 of the tacking pile 36 remains stationary with
respect thereto until the spear is completely inserted into the stacking
pile.
Depending downwardly from the spear 40 is a pusher plate 54
which engages a side-face 56 of the rem 38 and serves to move it laterally
as the spear 40 is inserting into the stacking pile 36. The pusher
plate 54 has a height at least slightly higher than the thickness of the
ream 38 being separated in order to provide clearance as seen at 58 be-
tweet the top sheet off the removed ream 38 end the belt 44 which is
moving around rollers 50 and 52~
The stacking pile 36 is normally supported by a lift table
comprising two free wheeling conveyors 60, 62 which engage a bottom
sheet 64 of the bottom ream in the stacking pile 36. The two conveyors
60, 62 comprise a split lift table which allows the reams to be supported
while the spear 40 is being inserted and withdrawn. The two conveyors
60, 62 are mounted for independent vertical movement such that the ream
and stacking pole 36 are continuously ~upported.as required.
As the spear is inserted into the stacking pile 36 the pusher
plate 54 move the ream 38 which is supported on the ruling con-
voyeurs pa 62 toward an air table 66. When the ream 38 is deposited on
the air table 66 a is shown in phantom, most of the weigh of the paper
it supported by an air Cushion from air supplied under pressure through
conduits 68 in the air table which ore exposed to a top surface 70 of
the table through individual air port 72. Longitudinal conveyor belts
glue
74, 76 which extend above the surface 70 of the air table 66 are used
to move the individual reams to the next station in thy paper processing
system.
As the spear is retracted from the stacking pile 36, the
smaller free-wheeling conveyor 60 moves vertically to support the bottom
of the stacking pile while the spear continues to be withdrawn. As soon
as the spear is withdrawn, the second conveyor 62 moves vertically to
alto support the stacking pile.
It is desired thaw the top sheet, represented by sheet 16 in
FIG. 1, of the stacking pile remain at the same level relative to the
rolls 26, 24 throughout the entire stacking operation. Therefore, the
spear 40, as well as the free-wheeling rollers 60, 62 us mounted for
vertical movement on a shaft 78. Also, as seen in FIG. 1, a housing 80
for the stacking pile 36 has a portion cut away at 82 corresponding to
the entry point of the spear 40 such that the spear it able to engage the
slacking pile 36 while the pile is still held within the housing 80 and
as the spear moves into thy stacking pile 36 it will also move downwardly
due to the additional eta being stacked ox the pile such that when it
reaches an opposite wall 84 of the housing 80 it will pass beneath a
lower edge 86 ox that wall.
In FIG. 2 where shown an alternative embodiment of the ream
separating arrange en in which the stacking pile aye, the spear motion-
is aye, the freewheeling conveyor aye and aye and the air table aye are
811 inclined to the same degree which allows for an enhancement of the
slacking and separating procedure, The air table aye has a side conveyor
belt I situated wherewith driven by motor 90 which moves the separated
reams aye to the next processing station a opposed to the bottom conveyor
belt 74 and 76 of the embodiment shown in FIG, 1. In all other respects,
the operation of this embodiment is the same as that shown no FIG. 1, this
embodiment merely utilizes the force of gravity in assisting in the
` I -6-
Z 2 I I%
alignment of the stacking pile aye and in the removal of the separated
reams aye.
FIG. 2 does show he Braille roller 24 in different rotational
position thin what shown in FIG. 1 and it it seen that a sheet of paper
92 it being passed between the rollers 24, 26 by means of the high-speed
tape mechanism 18. It is also seen that brush member 34 will contact the
tail end of sheet 92 causing it to drop down against roll 26 where the
pressure of the brush member 34 will cause the sheet 10 lying on the
roll 26 to accelerate and move into the stag pile aye.
FIG. 3 shows sun alternative embodiment of the jail stopping
and knockdown device of the present invention where it is seen that
individual sheets 110, 112, 114 and 116 are fed into a stacking pile
118 by mean of two high-speed tapes 120, 122 which convey the sheets at
speed up to 1500 fpm. The lower tape means 120 is supported at one end
by roll 124 and at an opposite end by a similar roll not shown and the
upper tape means 122 it supported by rolls 126, 128 end my additional
rolls not shown. The upper tape 122 extends further ruptured in FIG. 3
of the turnaround roll 124 of the bottom tape 120.
Downstream of the turnaround roll 124, there it provided an
alternative eDibodiment of the slowdowrl device of the present invention.
In the embodiment shown in FIG. 3, there it provided a tail-stopping devil e
which cruises Wylie rotating vacuum roll 130 and a blow down device in
dilated generally at 132. The vacuum roll 130 Jo rotated by means of an
electric motor 136. A blower shown schematically at 138 is used to
evacuate the alum roll 130 and to pressurize the hollow in~erlor of an
air nozzle 134.
The vacuum roll 130 ha series ox openings 140 there through
and us generally hollow, the blower 138 being arranged to evacuate the
hollow interior whereby causing air to be drawn radially inwardly in the
opens 140. Because of the large umber openings 140 in the roll 130,
the suction pressure at any one given opening 140 is relatively low.
The blow down device 132 comprises a generally cylindrical rotating
housing 142, disposed horizontally, which has a longitudinal slot 144
extending along its length which is disposed at the slowest portion of the
housing 142. The housing 142 surrounds the nozzle 134 which comprises
a generally hollow member having an elongated nozzle element 146 which
has a central passageway 148 extending radially outwardly in the nozzle
member. The housing 142 is drivingly rotated by the motor 136 about
its horizontal axis such thaw the nozzle passage 14~ will align with the
slot opening 144 in the housing 142 once during each revolution of the
housing 142.
The rotating housing 142 is in turn enclosed within an air box 150
which has a slot 152 wherein which can align with the rotating slot
144 of the rotating housing 142. Once during each revolution of the
housing 142 the slots 144 and 15~ will align and an air blast will exit
downwardly between the tape means 122 and against a tail end of a sheet
of paper, thereby forcing the sheet against the slowdown roll 130. As
the rotating housing 142 rotates, it Shuts off the air to slot 152 as the
lead edge of the next swept ox paper passes through thaw position.
A second, horizontally disposed slot 154 is provided in the
air box lS0 upstream of the first slow 152 which directs air in the
direction of the movement and which causes a venturi action between
the paper and the air box 150, whereby holding the lead edge of the paper
against the top tapes 122. In this manner, the lead edge of the following
sheet us lifted over the trailing edge of the reseeding sheet which is
overlying the tacking pile 118.
FIG. 4 shows an alternative embodiment of the tail topping
and knockdown device of the present invention where I is see that
individual sheet 160, 162 and 164 are fed into a stacking pile 166 by
meals of a whopped tape means 168 which conveys the keels at speeds
up to 1500 Em Tape means 168 is supported at one end by turnaround
I 2
roll 170 and at an opposite end by a similar roll not shown.
Immediately downstream of the turnaround roll 170, there
it provided a second alternate embodiment of a slowed device con-
strutted in accordance with the principals of the present invention.
In the embodiment shown in FOG. 4, there is provided a tail-stopping
device which comprises an osculating spring-loaded nip wheel 172 which
is actuated accurately by a signal which determines the location of the
sheet edge and gap in order to maintain its proper position on the trail-
in edge of the sheet.
The nip wheel 172 is rota tingly carried on the end of an arm
174 which pivots about a fixed point 176. The arm 174 is continuously
biased downwardly by spring means 178 and it is selectively urged up-
warmly by actuating means 180 such as a retracting piston.
A sheet location sensing means 180 is shown in FIG. 4 in the
form of an optical sensor hiving a light emitting or reflecting means 184
which causes light to be directed at the sensor 182 during the gap between
succeeding sheets of paper. The sensor 182 is connected to a control
means 186 which controls a valve means 188 connected to the piston 180.
At appropriate times the piston 180 is caused to by retracted thereby
lifting the nip wheel 172 to the position shim in phantom at 190. This
allows the sheet to travel past the nip wheel. Just prior to the tail
of the sheet passing the nip wheel 172, the control means 186 causes the
lifting means 182 release and the bias of the spring 178 causes the nip
wheel 172 to move downwardly to press the tail of the sheet against a
slowly rotating roll 192. In this manner, ho sheet is slowed and is
caused to drop into the jacking pile 166.
The slowly jot tong roll 192 it rotated by a motor means 194
and it con be of a vacuum roll type with an interior evacuated by a
blower means 196 and having a plurality of spaced openings 198 there-
through. An outer surface 200 of the roll 192 I rubber-covered or is
ox a high~frictioned material which Stacy the vacuum roll in gripping
the essay.
FIG. 5 shows an alternative embodiment of the tail-stopping
device shown in FIG. 1 which includes a plate 20~ dispose immediately
downstream of the turnaround roll 22 and Us upstream of a Sue
rotating roll aye which it shown to be a vacuum roll. In this embodiment,
each sheet is slowed down and passed to the stacking pile 36 individually
and immediately rather than sitting on the unnipped-slow-speed roll 26 of
FIG. 1, waiting for the next nip of the brush member I
s it appear from the foregoing specification, the invention
is susceptible of being embodied with various alterations and modifications
which may differ particularly from those that have been described in the
preceding specification and description. It should be understood that
we wish to embody within the scope of the patent warranted heron all
such modifications as reasonably and properly come within the scope of
our contribution to the art.
-10-
