U.S. patent number 3,785,256 [Application Number 05/184,875] was granted by the patent office on 1974-01-15 for panel counting, collecting and gating apparatus.
This patent grant is currently assigned to Westvaco Corporation. Invention is credited to Willem Andre Nikkel.
United States Patent |
3,785,256 |
Nikkel |
January 15, 1974 |
PANEL COUNTING, COLLECTING AND GATING APPARATUS
Abstract
A continuously conveyed series of uniformly dimensioned panels
of thin sheet material are counted and stacked from the bottom
against an abutment edge of a stationary but rotatable cam plate.
When a predetermined number of panels is collected in the stack,
the cam plate is rotated to lift the stack into a rotating roll nip
for conveyance to a second roll nip. Removal of the stack from the
proximity of the collecting cam plate is completed by the second
roll nip after the collecting cam has resumed a stationary,
collecting position.
Inventors: |
Nikkel; Willem Andre
(Covington, VA) |
Assignee: |
Westvaco Corporation (New York,
NY)
|
Family
ID: |
22678718 |
Appl.
No.: |
05/184,875 |
Filed: |
September 29, 1971 |
Current U.S.
Class: |
414/789;
414/794.9; 414/903; 414/790.7; 414/901 |
Current CPC
Class: |
B65H
33/08 (20130101); Y10S 414/115 (20130101); Y10S
414/101 (20130101); B65H 2301/42122 (20130101) |
Current International
Class: |
B65H
33/00 (20060101); B65H 33/08 (20060101); B31b
001/98 () |
Field of
Search: |
;93/93C,93DP ;214/6BA
;198/40 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Juhasz; Andrew R.
Assistant Examiner: Gilden; L.
Attorney, Agent or Firm: Richard L. Schmalz et al.
Claims
I claim:
1. Thin sheet material panel stacking and transfer apparatus
comprising:
a. panel delivery means providing a substantially continuous supply
of serially aligned thin sheet material panels;
b. counting means for discerning the delivery of a discrete number
of said panels and marking the event by emission of an actuation
signal;
c. stacking means for accumulating a stack comprising said discrete
number of panels in face-to-face and leading edge juxtaposition at
a stacking station;
d. stack removal conveyance means for removing a stack of said
panels from said stacking station; and,
e. stack transfer means for transferring the leading end of an
accumulated stack from said stacking station to said removal
conveyance means, said transfer means comprising a first roller
having a substantially full circle peripherial surface and a second
roller having a partial circle peripherial surface, said second
roller peripherial surface also comprising a notched portion
therein, said notched portion having an abutment surface for
receiving and aligning leading edge portions of said panels to
cumulatively form a stack leading end, said first and second
rollers being relatively aligned to nip said stack leading end
between said first roller peripherial surface and the circular
portion of said second roller peripherial surface upon rotation of
said second roller partial circle through a common radial plane
between the axes of said first and second rollers.
2. Apparatus as described by claim 1 wherein said panel delivery
portion comprises a first panel transfer plane and said stacking
means comprises a second panel transfer plane, said first and
second transfer planes intersecting at an obtuse included angle,
the length of said stacking station between said transfer means
abutment surface and the point of said transfer plane intersection
being less than the length of said panels whereby trailing end
portions of accumulated stationary panels project beyond said point
of intersection and each panel added to said stack is inserted at
the interface between said second transfer plane and the previously
added panel face.
3. Apparatus as described by claim 1 wherein said first roller is
operated in substantially continuous rotation.
4. Apparatus as described by claim 3 wherein rotational power
delivered to said transfer means is intermittently transmitted by
selectively engaged single revolution clutch means.
5. Apparatus as described by claim 4 wherein engagement of said
single revolution clutch means is prompted by said counting means
actuation signal.
6. In combination with delivery means providing a substantially
continuous series supply of thin sheet material panels; counting
means for discerning the delivery of a discrete number of said
panels; a stacking station for accumulating a stack of said
discrete number of panels in face-to-face juxtaposition; stack
removal means for conveying said stack from the proximity of said
stacking station; and cooperative roll nip propulsion means for
depositing said stack with said stack removal means; the
improvement comprising:
at least one roll of said nip cooperative provided with depressed
relief to the circumferential periphery thereof whereby said stack
may be drawn between said depressed relief portion and another roll
of said nip cooperative, when said one roll is stationary, said
depressed relief forming an abutment surface to align the leading
edges of said panels during said stack accumulation.
7. The combination as described by claim 6 wherein said delivery
means comprises a first panel transfer plane and said stacking
station comprises a second panel transfer plane, said first and
second panel transfer planes intersecting at an obtuse angle, said
stacking station having a length dimension extending along said
second panel plane between said one roll abutment surface to a
point beyond said first and second transfer plane intersection
whereby each panel added to an accumulating stack is inserted at
the interface between said second transfer plane and the previously
added panel face.
8. The combination as described by claim 7 wherein said other roll
of said nip cooperative is continuously rotating.
9. The combination as described by claim 8 wherein rotational power
delivered to said one roll of said nip cooperative is
intermittently transmitted by selectively engaged single revolution
clutch means.
10. The combination as described by claim 9 wherein engagement of
said single revolution clutch means is prompted by a signal emitted
by said counting means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the art of thin sheet material
handling and more particularly to the paper converting industry
wherein a paper web of indefinite length is drawn from a large roll
and cut into small panels of more convenient size, a discrete
number of the small panels being counted and collected in a
face-to-face stack for protective packaging and distribution.
2. Description of the Prior Art
In the process of converting paper from large roll stock, as
received from the finish end of a papermaking machine, to
individual packages containing a select number of uniformly sized
panels, it is customary to cut one rectangular panel dimension by
slitting as the web is reeled from the roll. The other panel
dimension is cut by rotary knives disposed transversely of the web
length as the web is fed continuously thereto. If it is desired to
collect these dimensional panels into face-to-face stacks
containing some particular number of panels, it is desirable to
count, collect and deliver the stacks as rapidly as received from
the transverse cutter. In the past, it has been necessary to run
the rotary knife and therefore the slit web supply at a speed below
capacity due to the greater time required of the counting,
collecting and delivery operations by prior art methods.
One such prior art method is that disclosed by U. S. Pat. No.
2,708,760 to Lewis C. Pearce. The significant shortcoming of such
prior art is the necessity to clear a completed stack of panels
from the collecting station before the arrival of the first panel
of the next stack.
It will be appreciated that the lateral structural integrity of an
aligned stack of paper panels to resist shear separation is
sustained only by the surface friction between individual sheets.
When the stack is accelerated from the static collecting position
by a dynamic force frictionally applied to the bottom panel,
inertia of the stack resists such acceleration. Any given stack of
panels, therefore, has a maximum lateral acceleration value whereat
the opposite acting inertia force exceeds the frictional force
holding the stack together.
Although, the frictional restraining forces may be augmented by
accelerating the stack between a roll nip, even this expedient has
a relatively low limit when compared to the velocity capacity of
current panel supply systems. Long panels, rapidly supplied with
short separation distances, quickly press the capacity of prior art
systems due to the fact that the first panel of a new stack will
close the separation gap between it and the last panel of a
completed stack and become entangled therein before the completed
stack may be removed from the collecting station. Accordingly the
supply velocity must be reduced to a magnitude commensurate with
that of the stack discharge period.
It is, therefore, an object of the present invention to provide a
rapid response, counting, collecting and stack transfer method and
mechanism wherein a succeeding stack may be started before the
preceding completed stack is completely removed from the collecting
station proximity.
Another object of the present invention is to provide a collecting
and transfer method and mechanism wherein a completed stack
discharge time period may overlap into the time period required to
collect a predetermined number of panels.
A further object of the present invention is to provide a
simplified collecting and discharge method and mechanism wherein
the stack aligning fence is integral with the discharge propulsion
roll.
SUMMARY
The foregoing objects of the present invention are served by a
rotary gate at the panel collecting station in the form of a
notched cam wheel. Only the ends of the panel stack need be
vertically supported by the notched cam.
Panel stacking at the collecting station is preferably from the
bottom up from an endless belt conveyor having a break in the
support plane at such a distance ahead of the notched cam as will
allow the panel trailing ends to spring up and above the leading
edge of oncoming panels.
Counting may be performed by any suitable means such as a
photoelectric sensor which will emit a trigger signal to an
electrically actuated single revolution clutch in the notched cam
power train.
As the collecting notch in the cam rotates, the gate abutment is
revolved away from the stack leading edge and simultaneously, the
supported end portion of the stack is lifted into a roll nip
between a constantly rotating overhead wheel and the back periphery
of the cam wheel. This action is necessary only to transfer the
stack end into a second, constantly turning, roll nip which
completes the stack removal.
Meanwhile, the notched cam completes the one revolution transfer
starting function and returns to the stationary collecting position
where a new stack is begun even before the completed stack is
completely removed from the collecting station proximity.
BRIEF DESCRIPTION OF THE DRAWINGS
Relative to the drawing wherein like reference characters designate
like or corresponding parts throughout the several views:
FIG. 1 is an elevational schematic of the invention in collecting
position;
FIG. 2 is an elevational schematic of the invention in the initial
stack transfer position;
FIG. 3 is an elevational schematic of the invention in the final
stack transfer position;
FIG. 4 is a dimensional comparison chart relative to the panel
length and cam wheel periphery;
FIG. 5 is an event sequence time comparison chart for the
invention;
FIG. 6 is an isometric view of the notched cam showing the one
revolution clutch in partial section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, there is shown an endless belt
conveyor 10 carrying a continuous series of thin sheet material
panels P. The source of panels P is irrelevant as to this invention
but in the normal use environment the panels are delivered with
uniform longitudinal dimension L (FIG. 4) and serially separated by
a gap G as the product of a continuous sheet web passing under a
rotary shear.
Since the stated functional objective is to assemble the series
continuum of single panels into face-to-face stacks, each
containing a predetermined equal number of panels, it is necessary
to first count the panels carried by the belt 10 past a fixed point
for the subsequent purpose of delineating a stack group for
segregation. This counting function may be performed by many known
devices which emit an electrical impulse when the set number of
panels P pass the reference point and automatically reset to start
the count over with the next successive panel. Selected for the
purpose of this disclosure is a photoelectric relay device having a
light emitter 15 for directing a collimated beam 16 across the
panel P conveyance path. A photon sensitive receiver 17 responds to
each interruption of the beam 16 when a panel P passes thereacross
by emitting a counting pulse. The series of counting pulses are
received by a digital counting relay (not shown) which conducts a
power signal when the predetermined number of count pulses have
been accumulated. Upon conduction of the power signal, the digital
counting relay circuit resets to start the count over again with
the next successive count pulse.
A slight break is provided in the conveyance plane of belt 10
between sections 10a and 10b as the belt 10 is drawn over turning
roll 12 by the belt pulling roll 11 at the terminal end of the
material transfer course. The length of belt section 10b and the
obtuse angular divergence thereof from section 10a is selected to
give an overhanging projection 14 to the trailing ends of panels P
above the belt section 10a approach to the plane angle break point
around turning roll 12. An air jet from conduit 13 supplements the
material rigidity of panels P to hold the ends 14 above the
approach plane 10a and further to gently urge the leading ends of
panels P to a flat entrance position into the wedge thereby
accumulating a stack of panels S from the bottom.
It is important to specify a belt 10 providing a static frictional
force between the surface thereof and a contiguous panel P face
that is greater than the maximum dynamic frictional force between
panels so that belt section 10a will deliver the final panel of a
stack S to its properly aligned position against the leading edge
abutment fence 22 in the notch 25 of gating wheel 20.
When the desired number of panels P have been accumulated, the
counting system emits a power pulse to a single revolution clutch
(FIG. 6) in the power train to cam wheel 20. As cam wheel 20
revolves (FIG. 2), point A at the circular periphery thereof lifts
the leading edge portion of the stack off the notch 25 support
surface 23, away from the fence portion 22, and into nip contact
with the constantly rotating transfer nip roll 21. Due to the rapid
response time of single revolution clutches of Type 6 as specified
by Bulletin No. 239, Jan., 1959, Hilliard Corporation, Elmira,
N.Y., and the fact that not all of the stack S mass is subjected to
acceleration parallel with the panel face shear planes, the surface
velocity of cam wheel 20 has matched the surface velocity of
transfer roll 21 by the time point A on cam wheel 20 reaches the
nip position of FIG. 2. Thereafter, removal of the entire stack S
from the holding position above belt section 10b is started.
As the circular periphery of cam wheel 20 between points A and B
opposite from the notch 25 continues rotational nip cooperation
with the transfer roll 21, the stack S leading edge is delivered
into the nip between constantly rotating removal rolls 30 and 31.
Transfer table 26 between wheel 20 and roll 30 may be useful to
prevent spreading of the individual panel ends during transfer from
one nip to the other.
As removal of a completed stack S progresses under the nip
propulsion of removal rolls 30 and 31, the first panel P of the
next stack continues unabated to advance along the final belt
section 10b beneath the trailing end 14 of completed stack S toward
the cam wheel 20 -- permissibly at a greater velocity than that of
the withdrawing completed stack. Since cam wheel 20 is stopped
after only one revolution, however, the fence 22 and end support
surface 23 is quiescently awaiting the arrival of said next first
panel. No interference is given the remaining portions of the
withdrawing stack S due to the relief clearance allowed by the
notch 25 in the stationary cam wheel 20 opposite from transfer roll
21. Accordingly, the completed stack is leisurely drawn from the
collecting station by the removal rolls 30 and 31 even after the
next stack has accumulated several panels.
Although obvious to those of ordinary skill in art from the
foregoing functional description of my invention, the disclosure
hereof may be better served by an expanded explanation of certain
design parameters and components. The first of such elucidations is
represented by the dimensions C and D of FIG. 1. Since the only
advancement of a stack S given by nip cooperation between wheels 20
and 21 is to deposit the stack with the nip between rolls 30 and
31, it is necessary that arc C of cam wheel 20 between points A and
B opposite from notch 25 be at least equal or slightly greater than
the centerline separation distance D between rolls 21 and 31.
Moreover, as illustrated by FIG. 4, distance D is less than the
length L of a panel P. The basis of these dimensional relations is
to assure that one revolution of the cam wheel 20 will securely
deposit a stack of length L within the propulsion nip between rolls
30 and 31.
Other critical parameters of my invention are the surface
velocities of the belt 10 and the rolls 20, 21 and 30, 31. These
velocities are coordinated with the foregoing length parameters to
yield a time-event sequence similar to that represented by FIG. 5.
In that figure, dimension g represents the maximum time lapse for
one revolution of the cam wheel 20. Dimension d is that time period
required to discharge a completed stack from the proximity of the
collecting station at notch 25. Dimension d' is the maximum period
allowable for the discharge of such completed stack. Dimension l is
the time lapse between the leading edge of one panel to the leading
edge of the next successive panel. Dimension k is the time interim
of a gap between the trailing and leading edges of two successive
panels. Dimension s is the time required for the accumulation of a
stack of 4 panels. Moments in the event sequence are measured from
the trailing edge point of a stationary panel at the collecting
station. At moment o, the trailing edge of the last panel P of a
stack S arrives at the reference point as represented by the minor
lineations under time intervals l.sub.1 through l.sub.4. Stacking
interval s is complete and a simultaneous pulse from the counting
relay engages cam wheel 20 to start the running of gating and
discharge period g and d, respectively. The period g must be equal
to or less than the period l so that when the trailing edge of the
first panel of the next stack arrives at the reference point at
moment 2, the cam wheel 20 is stationary in the collecting
position. Since the invention precludes interference between the
withdrawing stack and the newly accumulating stack, however,
interval d may be extended beyond moment 2 to as much as moment 8
when the next succeeding stack is complete and ready for
discharge.
A key element in the present invention is that of the single
revolution clutch 40 shown by FIG. 6 in partial section. Power
sleeve 41 is driven continuously by belt 42 running in sheave 43.
Cam wheel drive shaft 44 is selectively engaged with the power
sleeve 41 by a clutch mechanism 45 of the Sprag type which
comprises a cage 46 for roller cams 47. The geometry of cams 47 is
such that no rotational interference between race surfaces 41a and
44a is raised at one angular position of the cage 46 about the
centerline thereof. When the cage is rotated to a second relative
position, the cams 47 are wedged to a lock position between race
surfaces 41a and 44a. The cage 46 is spring biased to the lock
position. An abutment portion 48 on cage 46 is designed to
cooperate with frame mounted pawl 49 when urged to the engaged
position by spring 50. Disengagement of the pawl 49 from abutment
48 occurs at the instance of solenoid 51 actuated by the power
pulse from the counting relay.
When the pawl 49 is in the engaged position, attempted rotation of
the cage 46 thereagainst angularly displaces the cage 46 against
spring bias to the first, free running, or disengaged position.
Upon energization by a counting relay power pulse, the solenoid
shaft 51a momentarily lifts the pawl 49 off the abutment 48. Cage
spring bias angularly shifts the cage to the second, engaged
position thereby transmitting rotary power to drive shaft 44. Since
the counting relay pulse is only momentary, however, bias of the
spring 50 immediately urges the pawl 49 back against the cage ring
outer periphery 52 which slides thereon until contact with the
abutment 48 is resumed after one complete revolution.
It will, of course, be understood that various changes may be made
in the form, details, arrangement and proportions of the parts
without departing from the scope of the invention as set forth in
the appended claims.
* * * * *