U.S. patent application number 13/367783 was filed with the patent office on 2013-08-08 for driven nip rolls for sheet stacker infeed.
This patent application is currently assigned to MARQUIP, LLC. The applicant listed for this patent is James M. Krog, Richard F. Paulson. Invention is credited to James M. Krog, Richard F. Paulson.
Application Number | 20130200566 13/367783 |
Document ID | / |
Family ID | 48876269 |
Filed Date | 2013-08-08 |
United States Patent
Application |
20130200566 |
Kind Code |
A1 |
Paulson; Richard F. ; et
al. |
August 8, 2013 |
DRIVEN NIP ROLLS FOR SHEET STACKER INFEED
Abstract
In a sheet downstacker of a corrugator dry end, sheets are
delivered by a drive system driving both the bottom and top nip
rolls with a single motor that also drives the last flat belt sheet
conveyor to the nip.
Inventors: |
Paulson; Richard F.;
(Phillips, WI) ; Krog; James M.; (Phillips,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Paulson; Richard F.
Krog; James M. |
Phillips
Phillips |
WI
WI |
US
US |
|
|
Assignee: |
MARQUIP, LLC
Phillips
WI
|
Family ID: |
48876269 |
Appl. No.: |
13/367783 |
Filed: |
February 7, 2012 |
Current U.S.
Class: |
271/277 |
Current CPC
Class: |
B65H 2404/147 20130101;
B65H 2701/1762 20130101; B65H 29/14 20130101; B65H 2403/30
20130101 |
Class at
Publication: |
271/277 |
International
Class: |
B65H 5/02 20060101
B65H005/02 |
Claims
1. In a drive system for feeding a stream of shingled corrugated
paperboard sheets on a flat belt conveyor having a driven head
pulley to a stacker bay, including a sheet infeed nip defined by a
bottom nip roil and a top nip roll, the system comprising: a first
driving connection from the head pulley to a first shaft carrying
the bottom nip roll; a second driving connection from the head
pulley to a first idler sprocket rotatable mounted on a second
shaft carrying a nip roll support bracket; a third driving
connection from a second idler sprocket rotatably mounted on the
second shaft to a third shaft carrying the top nip roll; and, the
nip roll support bracket including a tubular member coaxial with
and carrying the second shaft, and the idler sprockets journalled
in one axial end thereof.
2. The drive system as set forth in claim 1, wherein the head
pulley and the first, second and third driving connections are
driven by a single motor.
3. The drive system as set forth in claim 1, wherein the first,
second and third driving connections comprise respective first,
second and third chain and shaft-mounted sprocket drives; the first
driving connection including a head pulley sprocket and a bottom
nip roll sprocket connected by a bottom nip roll drive belt. the
second driving connection including a second head pulley sprocket
and a first idler sprocket connected by a second drive belt; and
the third driving connection including a second idler sprocket and
a top nip roll sprocket connected by a top nip roll drive belt.
4. The drive system as set forth in claim 1, wherein the top nip
roll support bracket is pivotable on the axis of the tubular
member.
5. The drive system as set forth in claim 4, wherein the support
bracket includes a pair of parallel bracket arms interconnecting
the ends of the top nip roll with the respective ends of the second
shaft.
6. The drive system as set forth in claim 5, including an actuator
arrangement operatively connected to the support bracket to adjust
the vertical position and nip force of the top nip roil.
7. The drive system as set forth in claim 6, wherein the actuator
arrangement comprises a pair of fluid cylinders connecting the ends
of the second shaft with a pair of lever arms.
8. The drive system as set forth in claim 1, wherein the top nip
roll comprises a zero-crush roll.
9. The drive system as set forth in claim 3, including a top nip
roll drive chain tensioner positioned between the upper and lower
runs of the top nip roll drive chain.
10. The drive system as set forth in claim 1, wherein the second
driving connection includes a pair of upper idler tensioning
sprockets mounted horizontally spaced above the first idler
sprocket, and an adjustable chain tensioner interconnecting the
idler sprockets and positioning the second drive chain to back-wrap
around the first idler sprocket.
11. The drive system as set forth in claim 1, wherein the second
shaft comprises a stub shaft fixed to each end of the tubular
member.
12. The drive system as set forth in claim 11, wherein the first
and second idler sprockets are carried on one stub shaft.
13. The drive system as set forth in claim 12, wherein the first
and second idler sprockets are joined to rotate together.
Description
BACKGROUND
[0001] Corrugated paperboard sheets produced on the dry end of a
corrugator are typically shingled and then delivered to a
downstacker bay where the sheets are squared in a uniform stack fed
by a stacker infeed nip. The sheets exiting the nip and delivered
to the stacker descend with the infeed of sheets until a stack of a
desired number of sheets or height is achieved whereupon the stack
is removed and the stack support is returned to a position adjacent
the infeed nip.
[0002] Prior art stacker infeed nips have typically used a driven
bottom roll and an idler top roll with a cushioning or zero crush
cylindrical contact surface.
[0003] In stackers utilizing a single bottom drive roll for the
infeed nip, "back slip" or shingle compression can occur,
particularly if there are quality problems with the sheets being
stacked. Back slip or shingle compression may result in the buildup
of too much pressure in the nip and can result in product jam. Poor
product quality may also cause a jam at the stacker infeed nip.
When this occurs, cross machine direction slip of the sheets
entering the stacker bay is also a problem.
SUMMARY
[0004] It has been found that driving the top nip roll in synch
with the driven bottom nip roll can avoid all of the foregoing
problems. The driven top nip roll prevents back slip under heavy
drive conditions as the shingle is driven from both the top and the
bottom. This also addresses and alleviates the problem of cross
machine direction slip which, as indicated, reduces stack quality.
Finally, a lower nip force is sufficient to adequately handle the
shingle of sheets being delivered to the downstacker which further
minimizes the chances of board crush.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a schematic side elevation of a portion of a
corrugator dry end showing the positioning of the new nip roll
drive system of the present invention.
[0006] FIG. 2 is an enlarged side elevation of the nip roll drive
system.
[0007] FIG. 3 is a top perspective view of the drive system taken
from the opposite side.
[0008] FIG. 4 is a rear perspective view of the system looking in
the downstream direction.
[0009] FIG. 5 is a top plan view of the system with the head pulley
and bottom nip roll removed.
DETAILED DESCRIPTION
[0010] As is shown schematically in FIG. 1, the dry end 1 of a
corrugator typically includes two downstackers 2, each receiving a
stream of shingled sheets from a flat belt conveyor 3 comprising
one of a flat belt conveyor system that controls shingle movement
and coordinates discharge into one of the downstackers 2, all in a
manner well known in the art. Each of the downstackers 2 includes a
stacker bay 7 into which the shingled sheets are fed in a
stream.
[0011] The assembly of a stacker infeed nip 10 is mounted between a
pair of side frame members 5 at the upper inlet 6 to a downstacker
bay 7 and includes a bottom nip roll 11 and a top nip roll 12, both
of which are driven in synchronization by a head pulley 13 of the
last flat belt conveyor 3. The bottom nip roll 11 is of
conventional construction, as is the larger top nip roll 12 which
preferably has a zero crush surface 14. In the prior art, the zero
crush top nip roll 12 is simply an idler roll with the zero crush
surface that provides normal force on the corrugated sheets being
delivered through the nip 10 into the stacker bay 7. An arrangement
is typically provided to apply a variable normal force to the zero
crush roll and the sheets passing through the nip.
[0012] A first driving connection is provided by connecting a head
pulley sprocket 15 on one end of the head pulley 13 to a bottom nip
roll sprocket 17 mounted on the nip roll shaft 16. The sprockets 15
and 17 are connected by a bottom nip roll drive belt or chain 18
receiving its driving rotation from the head pulley 13, This and
the other driving connection may utilize either a steel roller
chain or a reinforced rubber timing belt. As used herein, the terms
are interchangeable.
[0013] A second driving connection is made between a second head
pulley sprocket 20 (preferably mounted on the opposite end of the
head pulley) and a first idler sprocket 21 mounted for rotation on
a stub shaft 19 above the head pulley 13. The driving connection is
made by a belt or chain 22, The stub shaft 19 is secured in the end
of a tubular member 27 forming part of a support bracket 23 for the
top nip roll 12.
[0014] A third driving connection is provided between a second
idler sprocket 24 rotatably mounted on the stub shaft 19 next to
the first idler sprocket 21. The second sprocket 24 is provided
with a driving connection to a top nip roll sprocket 25 by a nip
roll drive belt or chain 26. Stub shaft 19 is fixed in and provides
a pivot axis for the support bracket 23. Idler sprockets 21 and 24
are connected together so that sprocket 24 drives sprocket 25 via
chain 26. Sprockets 21 and 24 are journalled together on one of the
bearings that ride on stub shafts 19 at opposite ends of the
tubular member 27.
[0015] The nip roll support bracket 23 includes the tubular member
27 that is coaxial with and carries the stub shafts 19, which are
welded to the ends of tubular member 27 to provide the pivot
axis.
[0016] The support bracket includes a pair of parallel bracket arms
28 rigidly secured to the tubular member 27 and rotatably
supporting the top nip roll shaft 30, carrying the top nip roll, at
their respective opposite ends, The stub shafts 19 are carried in
end bearings 40 attached to the side frame members 5. The nip roll
support bracket 23 is strengthened and made more rigid with
triangular gussets 29 at the connections of the bracket arms 28 to
the tubular member 27.
[0017] An actuator arrangement 31 operatively connects the side
frame members 5 to the stub shafts 19 to adjust the vertical
position and nip force of the top nip roll 12. The actuator
arrangement preferably comprises a pair of fluid cylinders, and
more preferably, air cylinders 34. The rod ends of the air
cylinders 34 are connected to the ends of the stub shafts 19 with
pivot arms 35 such that the cylinders operate to move the top nip
roll 12 generally vertically with respect to the bottom nip roll 11
to adjust the nip force applied to the shingled sheets pulled
through the nip 10. As indicated above, the top nip roll 12
preferably comprises a zero-crush roll 14 to enhance the cushioning
effect on the sheets passing through the nip 10.
[0018] The first driving connection between the head pulley 13 and
the bottom nip roll 11 is positioned on one lateral side of the
drive system. The second driving connection between the head pulley
13 and the sprocket 21, and the third driving connection between
the sprocket 24 and the top nip roll 12 are positioned adjacent one
another on the other lateral side of the drive system.
[0019] The second driving connection includes a pair of upper idler
sprockets 32 that are mounted on one of the side frame members 5
and horizontally spaced above one end of the stub shaft 19 and
around which the chain 22 operates. An adjustable chain tensioner
33 is mounted between the upper idler sprockets 32. As may best be
seen in FIG. 4, the chain 22 is back-wrapped around the sprocket 21
to provide a driving connection in a compact assembly and ample
room for the top nip roll support bracket 23 and other components
of the system.
[0020] Tension in the top nip roll drive chain 26 is maintained by
a drive belt or chain tensioner 37 that includes a tensioner
sprocket 38 mounted to engage the upper run of the drive chain 26
and adjustable vertically by a lower adjustment screw 39 attached
to one of the bracket arms 28.
[0021] In addition to the improvements in stacker nip performance,
the infeed nip 10 uses the same motor driving the flat belt
conveyor 3 to drive the bottom and top nip rolls 11 and 12. This
provides a significant reduction in cost and improvement in overall
reliability.
* * * * *