U.S. patent number 3,742,798 [Application Number 05/191,429] was granted by the patent office on 1973-07-03 for corrugated sheet cutoff length adjustment apparatus.
This patent grant is currently assigned to Owens-Illinois. Invention is credited to Richard J. Gries.
United States Patent |
3,742,798 |
Gries |
July 3, 1973 |
CORRUGATED SHEET CUTOFF LENGTH ADJUSTMENT APPARATUS
Abstract
Apparatus for making immediate running changes in the length of
sheet cut from a continuous web of newly manufactured corrugated
paperboard. A corrugated cutoff knife is driven by the output shaft
of a bevel gear differential. A differential cage is driven through
a line shaft operating at the same speed as the running speed of
the corrugated board. The cutting knife is driven at the speed of
the board during the cutting stroke. However, the speed of rotation
during noncutting periods is retarded to allow a specific length of
board to pass under the knife. The input shaft to the differential
is driven during such periods to retard the speed of the cutting
knife. A pulse counter is preset to allow the input gear to be
driven only long enough to allow the desired amount of corrugated
board to pass before making the next cutting stroke. A control
panel is set with a next pre-selected length of sheet to be cut,
and by merely switching from the present length to a new length,
the counter is reprogrammed and a new length of sheet will be
delivered at once.
Inventors: |
Gries; Richard J. (Toledo,
OH) |
Assignee: |
Owens-Illinois (Toledo,
OH)
|
Family
ID: |
22705482 |
Appl.
No.: |
05/191,429 |
Filed: |
October 21, 1971 |
Current U.S.
Class: |
83/298; 83/324;
83/299 |
Current CPC
Class: |
B23D
33/00 (20130101); B23D 36/0041 (20130101); B26D
5/26 (20130101); Y10T 83/4691 (20150401); Y10T
83/4693 (20150401); Y10T 83/4775 (20150401) |
Current International
Class: |
B23D
33/00 (20060101); B23D 36/00 (20060101); B26D
5/20 (20060101); B26D 5/26 (20060101); B23d
025/12 () |
Field of
Search: |
;83/37,38,324,593,347,299,298 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Meister; J. M.
Claims
What I claim is:
1. Apparatus for cutting sheets of a preset length from a moving
continuous web of corrugated material produced by a paper
corrugating machine, said apparatus having the ability to
immediately change from cutting one length of sheet to cutting
another length of sheet and comprising, in combination:
a differential means including a rotatable cage, input and output
shafts supported by said cage, and a bevel gear differential
connected to said input and output shafts and carried by said
cage;
a ring gear drivingly connected to said paper corrugating machine
and attached to said cage for imparting rotational movement to said
cage;
means for severing said web of corrugated material, including at
least one rotatably mounted cutting cylinder carrying a cutting
knife and driven by said output shaft of said differential means,
to form individual sheets of said corrugated material; and
means for registering said differential backward while a
pre-selected length of corrugated material passes between said
means for severing said web and
for changing, upon demand, the amount of backward registration of
said differential between cutting of successive sheets of
corrugated material to thereby allow an immediate change from
cutting one length of sheet of corrugated material to cutting a
second length of sheet of corrugated material without cutting any
sheets of corrugated material of an intermediate length.
2. The apparatus of claim 1, wherein said means for registering
said differential backward and for changing, upon demand, the
amount of backward registration of said differential between
cutting of successive sheets of corrugated material comprises, in
combination:
rotating drive means connected to said input shaft;
a pulse generator attached to said input shaft for rotation
therewith for generating a representation of the degrees of
rotation of said input shaft;
a pulse transmitter for sensing and transmitting the pulses
generated by said pulse generator;
means connected to said pulse transmitter and said drive means for
limiting the rotation of said drive means to a pre-selected number
of pulse counts; and
means connected to said rotation limiting means for activating said
rotation limiting means after a sheet of corrugated material has
been cut.
3. The apparatus of claim 2, wherein said means for limiting the
rotation of said drive means comprises, in combination:
an operator-control panel having at least two independently set
values of degrees of rotation of said input shaft, the magnitude of
said value corresponding directly to the length of sheet to be cut
by said cutting cylinder;
a switch for selecting one of said values; and
an electronic control and logic unit connected to said
operator-control panel and preset to allow said drive means to
rotate only the number of degrees of said selected value, whereby
operating said switch to select another one of said set values will
cause an immediate change in the length of corrugated sheet cut by
said cutting cylinder.
4. The apparatus of claim 2, wherein said means for activating said
rotation limiting means comprises, in combination:
a plate cam attached to said output shaft for rotation therewith;
and
a switch controlled by said cam and connected to said means for
limiting the rotation of said drive means for turning said limiting
means on after the cutting of a sheet by said cutting cylinder.
5. The apparatus of claim 2, further including means connected
between said drive means and said input shaft for limiting the
rotation of said drive means to a single direction.
6. The apparatus of claim 2, further including means for holding
the rotational speed of said rotating drive means to a preset
percentage of the speed of said moving web of corrugated
material.
7. In a corrugated paperboard manufacturing process, wherein a
continuous moving web of corrugated material is severed to form
individual sheets by a rotating knife-carrying cylinder, a method
for driving said knife cylinder to allow immediate changes in the
length of sheet cut, comprising the steps of:
driving said knife cylinder with the output shaft of a bevel gear
differential;
driving a second cylinder covered with a resilient material mounted
in opposition to said first knife cylinder at a speed proportional
to the linear speed of said corrugated web;
driving said differential through a line shaft rotating at a speed
proportional to the linear speed of said corrugated web when said
web is to be severed;
registering said differential backward to retard the rotation of
said knife cylinder to allow a pre-selected length of web to pass
between said knife cylinder and said second cylinder before said
web is severed;
controlling the backward registration of said differential as a
function of the number of degrees of rotation of an input shaft of
said differential with an electronic logic unit;
feeding one of a plurality of rotational values of said input shaft
to said logic unit as a registration set point; and
inter-connecting said plurality of rotational values of said input
shaft and said logic unit with a multiple-pole switch, whereby any
one of said values may be selected as said registration set point
and changes in said set point may be made from one severed sheet to
the next.
8. Apparatus for cutting sheets of a preset length from a moving
continuous web of corrugated material produced by a paper
corrugating machine, said apparatus having the ability to
immediately change from cutting one length of sheet to cutting
another length of sheet, comprising, in combination:
a differential means including a rotatable cage, input and output
shafts supported by said cage, and a bevel gear differential
connected to said input and output shafts and carried by said
cage;
a ring gear drivingly connected to said paper corrugating machine
and attached to said cage for imparting rotational movement to said
cage;
means for severing said web of corrugated material, including at
least one rotatably mounted cutting cylinder carrying a cutting
knife and driven by said output shaft of said differential means,
to form individual sheets of corrugated material;
rotating drive means connected to said input shaft for registering
said differential backward;
control means connected to said drive means for limiting the
backward registration of said drive means to allow a pre-selected
length of corrugated material to pass between said means for
severing said web; and
switching means, connected to said control means, for changing,
upon demand, the amount of backward registration of said drive
means between cutting of successive sheets of corrugated material
to thereby allow an immediate change from cutting one length of
sheet of corrugated material to cutting a second length of sheet of
corrugated material without cutting any sheets of corrugated
material of an intermediate length.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to cutoff knives for corrugated
board manufacturing machines. More specifically, this invention
relates to an apparatus for adjusting the rotational speed of a
cutoff knife cylinder on a corrugated board manufacturing machine.
Most specifically, this invention relates to an apparatus for
changing the rotational speed of a corrugated board manufacturing
machine cutoff knife cylinder to allow immediate changes in the
length of sheets being cut from the continuous web of corrugated
material.
In the manufacture of sheets of corrugated paperboard material, it
is necessary to sever sheets of a desired length from a continuous
web of corrugated material manufactured by a corrugating machine.
The sheets are most commonly cut by counter-rotating knives mounted
on cylinders which shear the sheets at the desired length. In order
to achieve a clean cut, it is necessary that the peripheral speed
of the knives be equivalent to the lineal speed of the corrugated
material at the time the cut is made. Thus, if the lineal speed of
the corrugated web is kept constant, which is normally the
situation, the rotational speed of the knife cylinders must be
adjusted if a sheet of a different length is desired. The present
state of the art is illustrated by rotary cutoff mechanisms such as
the Model (JR) manufactured by the Langston Corp., 6th and
Jefferson Sts., Camden, N.J. 08104. This is an involved mechanical
linkage system which will allow the cylinders to rotate at a slower
rate during noncutting periods than during the cutting period, and
will allow adjustment of the overall speed of rotation of the knife
cylinders to compensate for different lengths of corrugated sheet
to be cut. However, this system has a serious deficiency in that it
is impossible to immediately change the length of sheet being cut.
That is, should one change from a shorter to a longer sheet, there
is a period of time in which sheets will be cut at intermediate
lengths between the shorter and longer sheets while the mechanism
is being adjusted. These sheets of intermediate length must be
trimmed by hand to the length of the original shorter sheet. In
addition, the increasing automation in the corrugated manufacturing
process requires that uniform length sheets be delivered to
automatic stacking apparatus at the end of the corrugating machine.
The intermediate length sheets produced during the sheet length
change cycle frequently jam such automatic equipment and lead to
production delays. The present invention overcomes this problem by
allowing the change in sheet length to be made from one cutting
cycle to the next cutting cycle, thereby changing immediately from
one sheet size to the next. This then allows the automatic stacking
equipment to be set up to receive one size and then diverted to
receive another size with the sheet sizes known to be uniform. In
addition, the intermediate length sheets do not appear and the
hand-trimming operation is eliminated.
SUMMARY OF THE INVENTION
My invention is an apparatus for immediately changing the length of
sheet cut from a moving web of corrugated material. A rotating
knife carrying cylinder is driven by a bevel gear differential
system. A second cylinder covered with a resilient material is
mounted in opposition to the first cutting cylinder and is driven
at a speed corresponding to the lineal speed of the corrugated web.
The bevel gear differential is supported in a cage which in turn
carries a ring gear that may be rotated to drive the bevel gear
cage. The ring gear in turn is driven through a line shaft at a
speed corresponding to the linear speed of progress of the
corrugated board itself. Thus, if only the ring gear were driven,
the knife cylinder would rotate at a speed equal to the lineal
speed of the corrugated material. This is the proper speed for the
cutting stroke of the knife cylinder. However, to cut different
lengths of corrugated sheets, the speed of rotation of the knife
cylinder must be retarded during the noncutting periods. To achieve
this, the bevel gear differential is registered backward to allow a
pre-selected length of corrugated board to pass.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view of the apparatus of the present
invention;
FIG. 2 is a schematic elevational view of the knife cylinder and
control cam of the present invention;
FIG. 3 is a perspective view partially in schematic of the
apparatus of the present invention as it would operate in severing
a corrugated sheet from a web of corrugated material.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, a knife cylinder 10 carrying a cutting
knife 15 is attached by an output shaft 12 to a bevel gear
differential 14. The bevel gear differential 14 is supported by a
cage 16. Carried by the cage 16 is an output gear 18 connected to
the output shaft 12, the output shaft 12 being supported by
suitable bearings 20 carried by the cage 16. An input gear 22 is
connected to an input shaft 24 which is supported by suitable
bearings 26 carried by the cage 16. Idler gears 28 and 30 are
provided and serve to interconnect the input gear 22 and the output
gear 18. The idler gears 28 and 30 are supported on stub shafts 32
and 34 which are carried in suitable bearings 36 and 38 in the cage
16. Attached to the cage 16 is a ring gear 40. Rotation of the ring
gear 40 will result in a corresponding rotation of the cage 16. The
entire assembly thus constitutes a mechanical adder with a scale
factor of one-half. That is, the angular displacement of the cage
16 equals one-half the sum of the angular displacement of the
output shaft 12 and the input shaft 24.
The ring gear 40 is driven by a line speed control gear 42. The
line speed control gear 42 in turn is driven by a line shaft 44
which is driven at a speed corresponding to the linear speed of an
advancing web 65 of corrugated material. A rotating drive means 46
is connected through a one-way clutch 48 to the input shaft 24. The
one-way clutch 48 prevents driving of the drive means 46 by the
input shaft 24. The rotating drive means 46 may be an electric
motor, or a hydraulic motor. In this preferred embodiment, the
rotating drive means 46 is shown as an electric motor and will be
referred to hereinafter as such. Attached to the input shaft 24 is
a pulse generator 50. The pulse generator 50 is of the type which
provides 360 pulses per rotation or one pulse per degree of
rotation. Since the pulse generator 50 is attached to the input
shaft 24, it is clear that the pulse generator 50 will measure the
rotation of the input shaft 24. A pulse transmitter 52 transmits
the pulses generated by the pulse generator 50 to a logic and
control unit 54. The logic and control unit 54 is of the type
well-known in the art which will remain on until a preset number of
pulses have been received from the pulse transmitter 52, at which
time it will turn off. The logic and control unit 54 controls the
on and off cycling of the electric motor 46. In turn, the logic and
control unit 54 is turned on and off by a roller-type switch 56,
whose functioning is controlled by a cam 58 attached to the output
shaft 12. The preset number of counts on which the logic and
control unit 54 controls, is introduced through an operator's
control panel 60. The operator's control panel 60 is such that the
operator may set two pre-selected number of counts on the control
panel 60. With a switch 64 thrown in one direction, one set of
counts will be used to control the logic and control unit 54. If
the operator throws the switch 64 to the other possible count
number, the logic and control unit 54 will then be responsive to
that preset number of counts.
To understand the significance of the counts generated by the pulse
generator 50, first assume that the minimum length of sheet to be
cut is 36 inches. In reality a shorter minimum could be set, but 36
inches is a convenient number to use for the purposes of this
explanation. In order to cut the 36 inch length, the cutoff knife
cylinder 10 must turn one revolution per 36 inches of corrugated
material fed forward. In a specific example using a 36 inch
circumference knife cylinder 10 at a 600 foot per minute corrugated
material travel, the knife would rotate at a constant 200
revolutions per minute. To cause this, the input shaft 24 would be
held stationary, and the ring gear 40 would be caused to rotate at
100 rpm. If at any time the line speed changed, the rotational
speed of the ring gear 40 would correspondingly change, since it is
driven through the line shaft 44. The net result of this drive
train is to allow the knife cylinder 10 to rotate at exactly the
line speed of the corrugated web 65 being fed forward. However,
should a different length of sheet be required, the knife cylinder
10 must travel at a rate slower than the line speed during a part
of its rotation to allow a greater length of corrugated board to
pass under it before it cuts. Nevertheless, at the time of cutting,
the knife cylinder 10 must be traveling at the same speed as the
corrugated web 65 which it is cutting. As an example, if the web 65
speed remains 600 feet per minute and a 72 inch long sheet is
desired, the average knife speed must be 300 feet per minute, but
must be 600 feet per minute at the time of cutting. The reduction
in speed necessary to cut longer sheets is accomplished by
providing a secondary input to the bevel gear differential 14 in
order to register the output of the bevel gear differential 14
backward. The formula describing the motion of this particular
mechanism is .theta..sub.40 =(.theta..sub.18 +.theta..sub.22)/2
where the subscripts 40, 18 and 22 refer to the gears 40, 18 and
22, and theta is the degrees of rotation of each of the gears. In
order to cut a 72 inch length, .theta..sub.18 must equal one
revolution per 72 inch of web travel. For 72 inch of web travel
.theta..sub.40 =360.degree.; for one cut, .theta..sub.22
=360.degree.. Therefore, .theta..sub.22 =2.theta..sub.40
-.theta..sub.18 = 360.degree.. It is quite obvious from these
calculations that any given length of sheet can be cut by turning
the gear 22 backward 10.degree. per inch of length in excess of 36
inches. Thus a 72 inch sheet requires a 360.degree. rotation of the
gear 22, and a 64 1/2 inch sheet requires a 285.degree. rotation of
gear 22.
Turning now to FIG. 2, the function of the cam 58 may be clearly
seen. In addition, it may also be seen now that a second cylinder
11 is mounted below the knife cylinder 10. The second cylinder 11
is covered with a resilient material into which the web 65 is
slightly imbedded as it is cut by the knife 15. The cylinder 11 is
driven by a line shaft 13 at a speed corresponding to the lineal
speed of advance of the web 65. This invention would also function
using the more conventional apparatus of both cylinders 10 and 11
carrying knives 15 to sever the web 65. However, less power is
required of the motor 46 if the combination of the knife cylinder
10 and the resiliently covered cylinder 11 are used as a means to
sever the web 65. The cam 58 is manufactured such that the knife
cylinder 10 is driven solely by the ring gear 40 through the
differential 14 for a period of approximately 45.degree. on either
side of the point of cutting the corrugated web by virtue of the
switch 56 being on the lobe of the cam 58 in which position, the
logic and control unit 54 is off. This insures that the knife
cylinder 10 is traveling at the proper speed at the time the cut is
made. After this period of cutting, the roller switch 56 is turned
off by virtue of dropping off of the lobe of the cam 58, thereby
energizing the logic and control unit 54, which in turn energizes
the electric motor 46 and begins counting pulses from the pulse
transmitter 52. It is important to realize that the cessation of
pulse counting and consequently the cessation of the rotation of
the electric motor 46 will not necessarily correspond to any
particular position on the profile of the cam 58. When the switch
56 once again rides up the lobe of the cam 58, it will turn off and
reset the logic and control unit 54. The point of cessation of
counting will occur when the input from the motor 46 has retarded
the angular displacement of the knife cylinder 10 by the amount of
web 65 length desired in excess of 36 inches. At the time of the
cessation of counting, the differential 14, through the ring gear
40 and cage 16, will drive the knife cylinder 10 at line speed
again until the point at which the cut is made. The speed of the
electric motor 46 is critical only in the sense that it must be
below the speed at which the knife blade 15 on the knife cylinder
10 would be brought to a complete halt. In the example given, this
would be a speed of 200 revolutions per minute corresponding to a
speed of 100 revolutions per minute of the ring gear 40. The closer
the actual operating speed of the electric motor 46 approaches this
maximum operating speed, the longer the theoretical length of sheet
which may be cut from the web. The system may be operated
successfully by knowing the maximum speed at which the line shaft
44 would ever be operated and setting the maximum speed of the
electric motor 46 correspondingly below this maximum speed. In a
modified and somewhat more sophisticated method shown in the
embodiment of FIG. 1, a tachometer 61 is attached to the line shaft
44 and transmits the line shaft speed to the logic and control unit
54. An additional circuit within the logic and control unit 54 is
set to control the speed of the electric motor 46 at a preset
percentage of the actual rotational speed of the line shaft 44 as
sensed by the tachometer 61.
Turning now to FIG. 3, the apparatus of the present invention is
shown in perspective view partially in schematic form. A continuous
web of corrugated material 65 is being severed by the knives 15 of
the knife cylinder 10. In addition, it may clearly be seen that the
operator's control panel 60 contains two separate segments 62 and
63 which may be individually preset to allow an immediate change in
the length of board to be cut. By merely dialing in the number of
pulses corresponding to the new width of board to be cut into one
of the segments 62 or 63 and throwing the operating switch 64 to
the new length set in the segment 62 or 63, the next sheet which
will be cut by the knife cylinder 10 will be of the proper length
with no intermediate sheets of varying lengths during the
transition from one length sheet to another. The two segments 62
and 63 have been found to be sufficient for the needs of most
commercial operations, since length changes are not made
frequently, and one segment may be reset while the other is being
used as a set point. However, the operator's control panel 60 could
contain a plurality of individually set segments, each for a
different set point value of degrees of rotation of the input shaft
24. A multiple pole switch corresponding to the switch 64 could
then be used to select one of the plurality of values for a set
point. It is understood that since the logic and control unit 54,
the electric motor 46, the pulse transmitter 52, the roller switch
56, the operator's control panel 60, and, when used, the tachometer
61 form a control circuit, all of these components are
interconnected by suitable electrical wiring means 59.
It will be understood that the logic and control unit 54, the pulse
generator 50, the pulse transmitter 52, the one-way clutch 48, and
the electric motor 46, all serve in combination as a means to
register the output of the differential 14 backward. It is possible
in theory to use a stepping-type motor in place of this entire
system. This type of motor is driven by a series of electrical
pulses and rotates a discrete amount per pulse. However, the
horsepower requirements for this invention are at present beyond
the capability of stepping-type motors, but future developments in
this area would allow the utilization of a stepping motor to
replace these components.
* * * * *