Note: Descriptions are shown in the official language in which they were submitted.
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STRIPPING DEVICE FOR A PRESS
FIELD OF THE INVENTION
The present invention concerns mechanical devices, more particularly to
mechanical devices for stripping waste from a pre-cut sheet of material.
BACKGROUND OF THE INVENTION
Presses for cutting sheet material such as paper, paperboard, cardboard and
the like, are well known. When the sheet material is pre-cut and includes pre-
cut portions, which need to be stripped out as waste pieces, the presses
include
stripping devices or stations. One such stripping station is disclosed in US
Patent No. 3,786,731, issued to Bobst et al. on January 22, 1974 for "Press
for
Cutting Sheet Material". Bobst discloses stripping stations, which include a
pair
of frames and a board, which has a series of pre-cut die openings, which are
shaped to the desired design. Stripping tools are mounted to the frames and
sandwich the waste material therebetween once the sheet material is moved
horizontally between the two frames. The stripping tools work together to
remove the waste material. One problem, however, the stripping stations may
operate too slowly for use with a high throughput stripping. US patent
No. 5,181,640, issued to Vossen et al. on January 26, 1993 teaches a stripping
station or device that works on similar principles, with a die punching the
waste
piece from the pre-cut material and passing through rollers which assist in
rolling the waste piece away from the sheet.
Unfortunately, for the devices taught by both Bobst et al. and Vossen et al.,
paper jams may occur frequently once the waste piece has been removed or
while the waste piece is being removed. For example, for the device shown by
Vossen et al., the waste piece may become stuck between the rollers. When a
paper jam occurs, the press and stripping device must be shut down, often for
a
significant amount of time, while the jam is removed. Such shutdowns are
frustrating for users and manufacturers and cause loss of both time and money
while the paper jam is removed.
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Accordingly, there is a need for an improved stripping device.
SUMMARY OF THE INVENTION
It is therefore a general object of the present invention to provide an
improved
stripping device that solves the above-mentioned problems.
An advantage of the present invention is that the stripping device can be
easily
retrofitted into an existing pressing machine to strip waste portions from a
pre-
cut sheet, without the need for complex machinery.
A further advantage of the present invention is the stripping device is
constructed from inexpensive materials.
Yet another advantage of the present invention is that, for the stripping
device
provided thereby, the occurrence of paper jams is significantly reduced or
eliminated.
Still another advantage of the present invention is that the stripping device
enables significantly increased stripping speeds and, therefore, more rapid
pressing of the sheets.
In accordance with an embodiment of the present invention, there is provided a
stripping device for stripping a waste piece from a sheet of material by a die
of a
press when the press is extended in a first direction through an aperture of a
frame of the press with which the waste piece is aligned, a first die end of
the
die tearing the waste piece from the sheet as the die extends through the
sheet
in the first direction, the device comprising:
- a resilient connecting portion having generally opposite first and second
connecting sides;
- a supporting finger extending from the first connecting side and having a
connecting end connectable to the frame; and
- a cogwheel rotatably mounted on an extending end of at least one arm
extending from the second connecting side and including at least three
adjoined peripheral faces connected to one another at corresponding
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edges, the cogwheel being aligned, in a first configuration for the device,
with one face of the peripheral faces facing the waste piece and the die
and being in register with the die and for rotating of the cogwheel by
sliding of the die along a portion of the one face with the waste piece
disposed therebetween as the die is extended in the first direction,
thereby deflecting the waste piece away from the sheet, and biasing the
cogwheel inwardly towards the supporting finger until the one face, in a
second configuration for the device, extends substantially alongside the
die in an orientation generally parallel to the first direction and in at
least
partial side contact therewith and a next adjacent face of the peripheral
faces is positioned for subsequent sliding of the die therealong with the
cogwheel being resiliently biased away from the supporting finger when
the die is removed from side contact therewith, the device being
returned thereby to the first configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will become better
understood with reference to the description in association with the following
Figures, in which:
Figure 1 is a simplified perspective view of a die cutting press with a pair
of
stripping frames showing an embodiment of a stripping device in accordance
with the present invention;
Figure 2 is a simplified exploded view of the stripping device shown in Figure
1;
Figure 3 is a simplified side view of the stripping device in a first, default
configuration;
Figure 4 is a simplified side view of the stripping device being initially
engaged
by a die of the press and having a cogwheel thereof rotated thereby out of the
first configuration while contacting a waste piece from a sheet of material;
Figure 5 is a simplified side view of the stripping device as the die
continues to
rotate the cogwheel and biases the cogwheel towards a supporting finger of the
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device, the die moving the device towards a second configuration as the waste
piece is removed from the sheet;
Figure 6 is a simplified side view of the stripping device in a second
configuration with the waste piece removed from the sheet and moving away
therefrom;
Figure 7 is a perspective view of a stripping device in accordance with an
alternative embodiment of the present invention; and
Figure 8 is a sectional view of the stripping device shown in Figure 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Figure 1, a press for pressing sheets of material, such as
paper, is shown generally as 10. The press 10 is used to remove waste pieces
of material 12 from pre-cut sheets of material 14, which is typically paper,
paperboard, cardboard and the like. The pre-cut sheet of material 14 is
typically
a template for many applications. Examples include, but are not limited to,
backing sheets for a blister package, blanks for constructing paperboard
cartons
and the like. The press 10 is a die-cutting press of a conventional design
known
to those skilled in the art and includes a pair of connected planar body press
frames 16, 18, which may be mounted within a housing, not shown.
Referring now to Figures 1 and 2, the frame 16 includes a number of pre-
shaped male dies (punches) 22. The frame 18 includes a corresponding
number of pre-shaped female body openings 24, which are complementary to
the male dies 22. The dies 22 and the openings 24 are pre-shaped according
to a required template design and the pre-cutting patterns on the sheets 14.
More specifically, the dies 22 and the aperture 24 are complementary to, i.e.
aligned with, the cut-outs 12 defining the waste pieces 12 in the sheet 14 for
tearing, punching, or otherwise removing the cut-outs 12, as waste pieces 12,
when the dies 22 are extended towards frame 18 and through apertures 24.
While rectangular or square shaped sheets 14 of material are illustrated
throughout, it is to be understood that any type of sheet 14 shape may be used
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without deviating from the scope of the present invention. Moreover, the
number of body apertures 24 and dies 22 may vary and depend on the design
requirements of the finished template for the sheet 14 with the waste pieces
12
removed.
5 Reference is now made to Figures 1 through 6. The stripping device of the
present invention is shown generally as 26 and is connected to the frame 18 in
proximity to an aperture 24, typically with at least one stripping device 26
for
each aperture 24. The stripping device 26 includes a stripping cogwheel,
shown generally as 28, a supporting finger 34 connected on a respective
connecting end 58 thereof to the frame 18 proximal the body aperture 24, and a
connecting portion 30 connecting at least one, and preferably first and
second,
cogwheel arms 36, on which the cogwheel 28 is rotatably mounted, to the
supporting finger 34. The connecting portion 32 is resilient and arcuate, i.e.
curved, with the supporting finger 34 located extending from a first
connecting
side 40 thereof and the arms 36 and cogwheel 28 located extending from a
second connecting side 42 thereof, generally opposite the first connecting
side
40 of the connecting portion 30. More specifically, the connecting portion
forms
a concave curve or arc extending between the first and second connecting
sides 40, 42 and the arms 36 and supporting finger 34. The cogwheel 28 on the
arms 36 is disposed towards, and preferably at least partially in, the body
opening 24 for intersecting and subsequent sliding contact with both the waste
piece 12 and a portion of the die 22, for example the first die end 23, on a
portion of the cogwheel 28 to strip the waste piece 12 away from the aperture
24 as the die 22 is passed through the aperture 24 in first direction shown by
arrow D1. Further, the supporting finger 34, arms 36, and connecting portion
30
are preferably configured, for example sized and shaped, such that the
cogwheel 28 extends at least partially beyond the connecting end 58 and at
least partially into the body aperture 24.
Referring now to Figures 2 through 6, the cogwheel 28 is described in greater
detail. The cogwheel 28 is rotatably mounted on at least one, and preferably
both, arms 36 on an axle 80 defining a rotational axis 82 for the cogwheel 28,
the axle 80 extending therethrough and being mounted in axle mounting
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apertures 78 situated in the extending ends 48. The cogwheel 28 has at least
three (3), and preferably four (4), adjoined peripheral faces 60, preferably
of
identical dimension and shape, which form the shape of the cogwheel 28.
Thus, for the embodiment shown, the cogwheel 28 is preferably square in
shape. The faces 60 are connected to one another at corresponding edges 62
which form corners between adjacent faces, for example 60a 60b. More
specifically, each face 60 has respective longitudinally opposed first and
second
corresponding edges, for example 62a, 62b for face 60a with a first, leading,
edge 62a being alignable proximal to and in partially overlapping register
with
the die 22, for a first configuration shown generally as 52 in Figure 3 of the
device, for intersecting the die 22 extending in direction D1 and subsequent
sliding contact of the die 22 with at least a portion of the face 60. The
sliding
contact, as explained below, by the die 22 with the waste piece 12 and the
face
60 causes the cogwheel to rotate in first rotational direction, shown by arrow
R1,
as the device 26 is moved, as shown in Figures 4 and 5, into a second
configuration shown generally as 54 in Figure 6. The second edge 62b of the
face 60 is situated distal the die 22 when the first edge 62a of face 60 is
aligned
proximal the die 22 and in register therewith.
Each face 60 preferably has a recess, shown generally as 64, situated between
the first and second edges 62 and which extends inwardly relative the
respective first and second edges 62 of the face 60, and therefore towards the
axis 82. More specifically, the recess 64 is preferably arcuate, i.e. curved,
and
thus curves concavely inwardly relative the edges 62 towards the axis 82. Each
recess 64 is preferably spaced apart from the first and second edges 62,
preferably equidistant thereto, first and second edges 62. More specifically,
each face 60 preferably has a respective first planar flat portion 66a,
extending
from the first edge 62 thereof to the recess 64, the respective first flat
portion
66a being alignable proximal and in at least partially overlapping register
with
the die 22, for the first configuration 52, for initial contact with the die
22. The
die 22 then moves in sliding contact with the first planar flat portion 64 and
waste piece 12 into the concave curvature of the recess 64, which facilitates
rotation of the cogwheel 22 in rotational direction R1 during stripping of the
waste piece 12. Optionally, each face 60 may also have a respective second
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flat planar portion 66b, generally planarly aligned with the first flat
portion 66a
extending from the recess 64 to the second edge 62b.
Referring now to Figures 2, 3, 4 and 5, the connecting portion 30, and
optionally
arms 36 and supporting finger 34, is resilient and made of a resilient
material,
such as hardened steel or resilient plastic. For example, for the embodiment
shown, the connecting portion 30 is a folded over, and thus curved, single
piece
of hardened steel. In the first, default configuration 52, in which the die 22
is
separated from the cogwheel 28 and one of the faces, say face 60a, faces
towards the die 22 and the waste piece 12 and sheet 14, the inherent
resilience
of the connecting portion 30, as well as of the arms 36 and finger 34 when
also
resilient, biases the cogwheel 28 away from the supporting finger 34 such that
the cogwheel 26 is aligned with the die in overlapping register therewith, and
specifically with the first flat portion 66a or edge 62a of the face 60a.
Thus, the
connecting portion 30, and optionally arms 36 and finger 34, automatically
aligns cogwheel 28, when the die 22 separated therefrom as in the first
configuration 52, for contact, initially on the first edge 62a or flat portion
66a,
with the waste piece 12 and the die 22 and subsequent rotation in rotational
direction R1, by sliding of the die 22 along the flat portion 66a and then
recess
64, with the waste piece 12 disposed therebetween, by extension of the die 22
in direction D1, shown in Figures 3 and 4. Thus, the waste piece 12 is
deflected, and thereby stripped, by friction between the sheet 14, die 22, and
face 60 away from the sheet 14 and through the aperture 24. It should be noted
that the face 60 may become briefly separated from the die 22 and waste piece
12 during the rotation of the cogwheel 28 in rotational direction R1, notably
as
the cogwheel 28 rotates of flips between the flat portion 66a and the recess
64,
which only facilitates stripping in that the waste piece 12 may then freely
fall or
be deflected away, as described above, from the sheet 14.
Reference is now made to Figures 3, 4, 5, and 6. As the die 22 continues to
move in direction D1, sliding along recess 64 towards second edge 62b and
second flat portion 66b, the die 22 pushes or biases the cogwheel 28 inwardly
toward finger 34, especially as the die approaches the outward curving recess
portion 68 of recess 64 leading up to the first flat portion 66a and edge 62a.
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Concurrently, the ongoing movement of die 22 in first direction D1 and sliding
along face 60a continues to rotate the cogwheel 28 in rotational direction R1
moving the second edge 62b and flat portion 66b of face 60a towards the die 22
and a next adjacent face 60b of the cogwheel 28 towards a position facing the
aperture 24 until the device is in second configuration 54. In the second
configuration 54, the face 60a extends substantially alongside the die 22 in
an
orientation generally parallel the first direction D1 and in at least partial
side
contact with the die 22, and preferably with both first and second edges 62a,
62b and flat portions 66a, 66b in side contact with the die 22, which inwardly
biases the cogwheel 28 towards the finger 34. The next adjacent face 60b, for
the second configuration 54, is positioned facing the aperture 24, preferably
perpendicular the die 22. Thus, in the second, compressed, configuration 54,
the next adjacent face 60b is thus oriented for subsequent sliding of the die
22
therealong, once the die 22 is removed from side contact with the face 60a,
for
example when the die 22 is retracted in opposing second direction D2, which
causes the cogwheel 28 to be biased resiliently away from the finger 34, thus
placing the adjacent face 60b in overlapping register with die 22 and
returning
the device 26 to the first configuration 52 for punching and stripping of the
waste
piece 12 from a new sheet 14. Thus, the device moves, automatically and
conveniently, from first configuration 52 to second configuration 54, and back
to
first configuration, with the cogwheel 28 rotated in the first rotational
direction
R1 to position the next adjacent face 60 for subsequent stripping of the next
waste piece 12 as the die 22 is inserted and removed through the aperture 24
to
remove the waste piece 12 from the sheet 14. This continuous and automatic
realignment of the device 26 for subsequent stripping allows for increased
speed of processing with the press 10. Further, deflection of the waste piece
12
reduces risks of paper jams.
To ensure that the cogwheel 28, and more specifically the next adjacent face
60
is properly aligned with the die 22 when the die 22 is removed from contact
therewith during return of the device 26 from the second configuration 54 to
the
first configuration 52, the device 26 may optionally have a ratchet
arrangement,
shown generally as 90, connected to the cogwheel 28, which impedes rotation
of the cogwheel 28 in a second rotation direction R2 generally opposed to the
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first rotation direction R1. The ratcheting arrangement 90 generally includes
at
least one ratchet wheel 94, well known in the art, having ratchet teeth 96,
96'
disposed circumferentially therearound and at least one ratchet finger 98 for
each ratchet wheel 94. Ratchet teeth 96', positioned alternately with teeth
96,
are typically flattened and are generally used to prevent small rotational
wobbling of cogwheel 28 relative to arms 36 and ratchet fingers 98, when
stopped thereby. For example, and as shown in Figure 2, the ratchet
arrangement 90, may have first and second ratchet wheels 94, connected to the
cogwheel 28 in alignment with a wheel side 92 of the cogwheel 28 and mounted
on the axle 80 therewith, and first and second ratchet fingers 98. The first
and
second ratchet fingers 98 are configured, for example positioned and aligned
connected to and extending form the arms 36, for contact with the ratchet
wheel
94, notably the teeth 96 thereof, whenever the cogwheel 98 is rotated. The
ratchet fingers 98 and teeth 96 are further configured, as is typical of most
ratcheting arrangements known in the art, such that a portion of the ratchet
finger 98 will be abuttingly immobilized against one of the teeth 96 or become
abuttingly immobilized therein when the ratchet wheel 94 and thereby the
cogwheel 28 is rotated in direction R2. Thus, the teeth 96 abuttingly stop
rotation of the cogwheel 28 in rotational direction R2, essentially limiting
rotation
of the cogwheel 28 to first rotational direction R1. Advantageously, impeding
of
the rotation of the cogwheel 28 in rotational direction R2 also reduces the
risk
that the waste piece 12 will be pulled in that direction R2, thus reducing the
risk
of the waste piece 12 jamming in the aperture 24 or another part of the
press 10.
To ensure that the resilient action of the connecting portion 30, and arms 36
and
finger 34 when resilient, do not result in the cogwheel 28 being biased too
far
away from the finger 34, upon release from the second configuration 54, at
least
one arm 36 has a respective arm hooking member 100 connected thereto and
extending towards the said supporting finger 34. For each arm hooking
member 100, there is a respective finger hooking member 102 extending from
the supporting finger 34 towards the arm 36. Each arm hooking member 100
has an arm member flange 104 extending therefrom towards the finger hooking
member 102 and each finger hooking member 102 has a respective finger
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member flange 106 extending therefrom towards the arm hooking member 100.
The hooking members 100, 102 and flanges 104, 106, forming a device
retaining member against opening of the device 26 in preventing the arms 36
from moving away from the finger 34 beyond the first configuration 52, are
5 configured, for example sized, shaped, or positioned, such that the arm
member
flange 104 is configured slidably movable, i.e. in sliding contact with the
finger
hooking member 102 between the finger member flange 106 and the supporting
finger 34, with the arm member flange 104 abuttingly hooking against the
finger
member flange 106 when the device 26 is in the first configuration 52, which
10 stops further movement of the cogwheel 28 away from the supporting finger
34.
The hooking members 100, 102 and flanges 104, 106 thereby prevent resilient
biasing of the cogwheel 28 beyond said first configuration 52 when the die 22
is
removed from side contact with the cogwheel 28. As shown, there are
preferably first and second arm hooking members 100 with respective arm
member flanges 104, finger hooking members 102, and finger member flanges
106 therefor.
Alternatively, and as shown in Figures 7 and 8, an alternative embodiment of
the device 26' may have a cap, shown generally as 130, forming a device
retaining member and which covers both sides 40, 42 of the connecting portion
30, and optionally over a portion of the arms 36 and support finger 34. The
cap
130 is sized and shaped such that the connecting portion 30, the support
finger
34, and arms 36 abut with inner cap walls 132 of the cap 130 when the device
is
in the first configuration 52, with the cogwheel 28 being rotated and biased
inwardly as previously described when the device 26 is moved into the second
configuration 54. Thus, as with members 100, 102, which may be omitted when
the cap 130 is deployed, the cap 130 abuttingly stops the arm 36 from biasing
outwardly relative the support finger 34 beyond the first configuration 52.
The
cap 130 is typically connected to the connecting end 38 using bolt or screw
112
which connects a connecting member 134 of the cap 130 configured for
extending along and over the support finger 34 to the connecting end 38.
The extending ends 48 may, optionally, have tapered slots 84 which flare
outwardly from the mounting apertures 78 and through which the axle 80 may
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be inserted and then snappably placed or inserted into the mounting apertures
78. Thus, the cogwheel 28 and axle 80 may be easily and removably mounted.
As shown in Figure 2, an optional spacer 110 may be included with device and
which may be connected between the connecting end 58 and the frame 18 with
screw or bolt 112 inserted through screw apertures 114 and securely engaged
in a corresponding screw hole 114' of the frame 18. The spacer 110 spaces the
connecting end 58 further away from the frame 18, and thus may be deployed
to space the cogwheel 28 further away, or less further into, the aperture 24
than
would be the case if the connecting end 58 alone was connected to frame 18
with screw 112.
Connecting end 58, as well as spacer 110, typically includes at least one,
preferably two, rotational locking and positioning guides 111 adapted to
engage
corresponding guide slot holes 113 of the frame 18 adjacent screw hole 114'.
When spacer 110 is used, the latter typically includes guide recesses 115 to
guidingly receive the positioning guides 111 of the connecting end 58 therein.
The positioning guides 111 with corresponding slot holes 113 prevent any
possible rotation of the device 26 about the screw axis that would move the
cogwheel 28 away from the corresponding die 22, and therefore prevent proper
operation of the device 26.
While specific embodiments of the stripping device have been described, those
skilled in the art will recognize many alterations that could be made within
the
spirit of the invention, which is defined solely according to the following
claims.
