Note: Descriptions are shown in the official language in which they were submitted.
F-0916 -1-
SPLAYED ROLL FOLDER FOR
Adhesive closures for bags, such as thin plastic sandwich
bags, have been widely used. A transverse adhesive streak near the
mouth of a sandwich bag is generally preferred for this purpose.
However, a streak of exposed and unprotected adhesive adjacent to the
mouth of such a bag structure has presented many drawbacks. When these
bags are packaged within a dispensing carton, either in continuous roll
form or individually adjacent to one another, the bags have a tendency
to stick to one another as well as to exterior objects following
dispensing of individual bags from the container, thus making it
difficult to utilize the bags. In addition, the adhesives which are
used are necessarily relatively non-aggressive in an attempt to
alleviate such problems, thereby making the closures less effective
than would otherwise be possible.
An improved Z-fold adhesive striped closure has been described
in U.S. Patent 3,990,627 for protecting an adhesive streak extending
across the front wall flap of a small bag, such as a sandwich bag. A
fast and simple method and apparatus for making such Z-folds or pleats
in a continuously advancing sheet is needed however, particularly in
the manufacture of sandwich bags which are serially connected in roll
Norm by a perforated or weakened structure.
An additional device of the prior art has long been used for
closing large plastic bags, such as trash bags. This device is a
flexible strip ox material such as paper, enclosing a bendable piece of
metal wire. Such strips are commonly placed in the box of trash bags
as an easily ruptured sheet or are adhesively attached to each bag by a
piece ox tape.
However, it would be far preferable to have each strip as an
integral part of the bag structure. A convenient means for doing so it
an adhesively secured pleat within which the closure strip is disposed
but no method or apparatus is available for forming such a pleat and
I
F-0916 -2-
placing the strip therein. Similarly, a drawstring can be placed
within a pleat for subsequently closing the mouth of a bag by pulling
upon both ends of the drawstring and then tying it.
A third area of interest in the prior art is the opening of
plastic bags and other containers, such as foil-laminated bags for food
products, shipping bags for fertilizer, animal feed and the like. Many
of the bags are so tough and difficult to open that a piece of wire or
string is sometimes attached to the bag structure to serve as a cutting
tool. However, using the wire or string for its intended purpose is
not always easy. A simple and reliable device for incorporating the
wire or string into the bag structure and for readily using it to open
the bag by slicing through the sheet material thereof would be a
distinct advance in the art. A pleat enclosing the cutting material
~ould~provide this structure, but again the prior art provides no
method or apparatus therefore
The present invention solves these prior art problems and
provides a method and apparatus for making a pleat which selectively
encloses a streak of adhesive a length of metal wire, a string, or
another useful object for a variety of sealing, tying, or cutting
purposes as desired by the user of structures incorporating the pleat
which is made in a continuously advancing sheet of flexible material of
indeterminate length, such as polyethylene or polypropylene film.
me apparatus of this invention, for folding a strip in a
continuously advancing sheet of indeterminate length and for forming a
pleat in the sheet, broadly comprises, in combination:
A. a tensioning means for subjecting a reach of the sheet to
tension along a line of departure that is transversely disposed to
the sheet; and
. a composite roll, comprising:
1) a composite peripheral surface which receives the
reach along a line of arrival thereon, the sheet thereafter
traveling over the composite peripheral surface through a
peripheral distance,
..
.
F~0916 -3
23 an imaginary axis of rotation that is disposed in
? parallel to the line of departure and
3) two parts, having: -
a) axes of rotation which are inclined towards each
other at a pleat angle, and
b) adjacent circular sides which form a circularly
converging gap and are in revolving contact along a pinch
zone, the tensioning means being disposed so that the
peripheral distance extends through a peripheral angle of
from 45 to 180 between the line of arrival and the pinch
zone.
As one specific embodiment, the tensioning means comprises a
first roll, having a first axis of rotation and a first peripheral
surface on which the line of departure is disposed. In combination
therewith, a first nip roller is in rolling contact with the first
peripheral surface to form a first nip there between, the sheet being
arranged to pass through this first nip In further combination with
the first roll, a second nip roller is in rolling contact with the
composite peripheral surface to form a second nip there between at the
pinch zone, the sheet similarly being arranged to pass through this
second nip. As thus combined, the apparatus is most suitably arranged
to operate with a peripheral distance of 90.
As another specific embodiment in combination with the first
roll, the two parts are:
A. a first component roll which has a second axis of rotation
and a second peripheral surface; and
B. a second component roll which has a third axis of rotation
and a third peripheral surface, the third axis ox rotation being
inclined at the pleat angle to the second axis and the third axis
of rotation appearing to be disposed in parallel to the first axis
when viewed in parallel to the reach, whereby the peripheral
distance is 90~.
Lo
F--0916 - pa -
The foregoing aspects of the invention are
also disclosed, and are claimed, in Canadian Patent No.
1,199,894 of FUJI erring ton issued January 28, 1986,
of which the present application is a divisional
I
A
~%~
F-0916 I
s In general, the depth of a pleat is one half ox the width of
the strip that is measured on the first peripheral surface. This depth
is measured, at a 90 wrap of the film over the composite peripheral
surface, by the formula: 1/2 projected distance x tangent of the pleat
angle, the projected distance being the length of the reach plus the
radius of the composite roll.
As a further specific embodiment, the first component roll is
substantially wider than the second component roll. The first
component roll is therefore generally disposed in parallel to the first
axis of rotation, and the second component roll is an inclined roll.
The parallel and inclined rolls are operably arranged so that
the circular side of the parallel roll, along the circularly converging
gap, has a beveled surface adjacent to the second peripheral surface,
and this beveled surface is beveled at the pleat angle from the
perpendicular to the second peripheral surface. As one embodiment
thereof, a portion of the beveled surface, adjacent to the second
peripheral surface, herein is termed a pleat surface and the remaining
portion thereof is termed a drive surface. A circumannular recess is
provided in the circular side of the inclined roll or is alternatively
provided in the pleat surface of the parallel roll. It is additionally
satisfactory to provide mating recesses in the circular sides of both
rolls.
This circumannular recess has an axially measured width
equaling at least twice the thickness of the sheet, and, as a
practical matter when a streak of adhesive is to be enclosed within the
pleat, the width of the circumannular recess additionally equals the
thickness of the streak, because it is generally not desirable to
spread or smear the adhesive. Further, this width additionally equals
the thickness of a cutting or closing device it it is to be enclosed
within the pleat.
The circumannular recess has a radially measured width which
is slightly greater than the width of the pleat and is equal to the
radially measured width of the pleat surface. The circumannular drive
F-0916 -5-
surface, which is in rolling contact with a portion of the circular
side of the inclined roll while passing by the pinch zone, is disposed
radially inwardly of the recess.
As one specific embodiment, the third peripheral surface is
the surface of a right circular cylinder, and as another embodiment,
the third peripheral surface is the surface of a right circular cone.
Indeed, the third peripheral surface is inclined at a bevel angel,
measured from the third peripheral surface to the perpendicular to the
circular side of the inclined roll, which can vary from 0 to 5. In
general, this bevel angel is one half of the pleat angel, and the pleat
angel is prom 0.25 to 5, preferably being 1.5.
In the apparatus comprising a parallel roll and an inclined
roll, the inclined roll is rotatable supported by a bearing assembly.
The apparatus also comprises a hinged mounting assembly to which the
bearing assembly us attached. A biasing means for pressing the
inclined roll toward the parallel roll, whereby the inclined roll is
driven entirely by contact of its circular side with the drive surface
within the vicinity of the pinch zone, exerts a force at the drive
surface that is from one pound to ten pounds.
A method for pleating a continuously advancing flexible sheet
of indeterminate length according to this invention broadly comprises
the following steps:
A. passing the sheet as a reach under selectively varied
tension from a line of departure to a line of arrival; and
B. passing the sheet under this tension and over a composite
peripheral surface from the line of arrival to a pinch zone,
through a peripheral distance subtended by a peripheral angle of
from 45 to 180 and over a circularly converging gap having a
pleat angle of from 0.~5 to 5 and ending at the pinch zone.
The pleat angle is suitably 1.5 and the peripheral angle is
suitably 90. Under these conditions, tension is exerted
perpendicularly to the line of departure on one side of the gap and is
oblique to the line of departure on the other side of the gap.
F-0916 -6-
An improved method for forming and protecting an adhesive
streak, in the manufacture ox adhesive closure bags, is provided by
this invention, comprising the following steps:
A. longitudinally depositing the streak, having a selected
adhesiveness along a selected strip on one side of a
continuously advancing sheet of indeterminate length; and
B. longitudinally pleating the strip, whereby the streak is
entirely within the pleat and is adhesively attached to at least
one interior surface ox the pleat, by:
1) passing the sheet under a selected tension prom a
striper roll to a composite roll which comprises a parallel
roll and an inclined roll, this strip being approximately
aligned with a circularly converging gap which is formed
between the peripheral edge ox the parallel roll and the
adjacent peripheral edge of the inclined roll, and the
adjacent circular sides of the inclined and parallel rolls
being in rolling contact in the vicinity of a pinch zone at
the convergence of the edges, whereby the sheet is
longitudinally divided into a portion having parallel tension
between the stripper roll and the parallel roll and a portion
having oblique tension between the stripper roll and the
inclined roll;
2) during the passing, transversely moving the oblique-
tension portion toward the gap; and
I forcing a strip of the oblique-tension portion into
the gap to Norm the pleat.
The gap generally subtends a pleat angle of from 0.25 to 5 and is
most suitably 1.5.
The width of the strip varies directly with the distance ox
the passing operation between the striper and composite rolls and
additionally varies directly with the pleat angle. The forcing
operation occurs through a peripheral wrap-around distance subtended by
a peripheral angle of 45 to 18û. Specifically, at a peripheral angle
ox ED the width of the strip is measured by the tangent of the pleat
I
F-0916 I
angle times the projected distance from the line of departure on the
striper roll to the pinch zone. Although it is not necessary, the
inclined roll is usually biased toward the parallel roll.
Alternatively, or in combination with such biasing, the contact surface
of the rolls may be provided with abrasive an roughened surfaces, as is
known in the clutch art.
For sandwich bags and most consumer products, the streak of
adhesive is a continuous length of a selected adhesive. However, the
adhesive may alternatively be added at spaced intervals along the strip
in order to secure a bendable segment which is placed in contact with
the spaced adhesive and is aligned with the strip. This bendable
segment may be a length of tying wire, a length of cutting wire, or a
drawstring, to be used alternatively for closing or opening the bag.
In thy drawings appended to this specification:
Fig. 1 is a schematic side view of an apparatus for pleating a
continuously advancing sheet of plastic material having an
indeterminate length.
Fig. 2 is a schematic plan view of the striper roll and the
composite roll of the invention, looking in the direction of the arrows
2-2 in Fig. 1, with arrows illustrating the parallel and Saudis
movements of the sheet over the reach between the lines of contact of
the sheet with these rolls and into the circularly converging gap
between the inclined and parallel parts of the composite roll.
Fig. 3 is a schematic top view, taken in the direction of the
arrows 3-3 in Fig. I ox the striper roll and of a particular
embodiment of the composite roll seen in Figs. 1 and 2.
Fig. 4 is a sectional view of a portion of the composite roll
of Fig 3 at the pinch zone between inclined and parallel parts of the
composite roll.
Fig. 5 is a schematic top view taken in the direction of the
arrows S-5 in Fig. 1, of another specific embodiment of the composite
roll seen in Figs. 1 and 2.
Fig. 6 is a sectional view of a portion of the composite roll
of Fig. 5 at the pinch zone thereof, similar to Fig. 4.
F-0916 -8-
Fig. 7 is a sectional view through the reach of a film sheet,
looking in the direction of the arrows 7-7 in Fig. 1, showing the pleat
as it is being initially formed.
- Fig 8 is another sectional view through the film sheet and
the underlying composite roll, looking in the direction of the arrows
8-8 in Fig. 1, showing the plea being folded further within the
circularly converging gap ox the composite roll.
Fig. 9 is a longitudinal sectional view of the inclined and
parallel parts of the composite roll, showing the system of
angular-contact ball bearing used for support thereof.
Fig 10 is a longitudinal sectional view of the inclined part
ox the composite roll and of the hinge biasing device therefore taken
at 90 to the section shown in Fig. 9.
Fig. 11 (located in the fourth sheet of drawi~gs,with Figs. 7
and 8) is a schematic plan view of a striper roll, a n~lti-piece roll,
and a sheet passing between these rolls, similar to Fig. 2.
Fig. 12 (located in the fourth sheet of drawings with Figs. 7
and 8) is a schematic sectional view through a sheet having a plurality
of pleats after it has passed over the multi-piece toll of Fig. 11.
Fig. 13 (located in the second sheet of drawings, with Figs. 3
and 4) is a sectional elevation through both sides of a two-pleat trash
bag having a drawstring pleat or holding a drawstring and closing the
top of the bag and a sealing pleat for forming a sealing strip, the draw-
string and sealing pleats having been made on the save side of the film.
Fig. 14 (located in the second sheet of drawings, with Figs. 3 and
4) is a sectional elevation through a trash receptacle of conventional
plastic construction Unto which the bag ox Fig 13 has been mserted and to
the sides of which this bag has been adhesively attached.
Referring to Fig 1, the apparatus ox this invention broadly
comprises a first nip roller assembly 10, a striper roll 20, a
composite roll 30, and a second nip roller assembly 40.
The first nip roller assembly 10 comprises a roller 12, having
a peripheral surface 11 and an axis of rotation 13, and an arm 15 which
is pivotal attached at one end to a frame (not shown in the drawings)
F-0916 I
and is rotatable attached at its other end to a pin at axis 13. The
striper roll 20 comprises a peripheral surface 21 and an axis of
rotation 23.
A continually advancing sheet 50 of indeterminate length, as
shown in Fig. 1 and 2, approaches the apparatus as reach 51, passes
under first nip roller 12 through a nip 19 between roller 12 and roll
20, and continues over surface 21 of striper roll 20l through a
peripheral length measured by angle 28, to a line of departure 27. The
sheet of film 50 passing over surface 21 through peripheral distance 28
is readily available for depositing at least one streak of adhesive 29
upon its outer surface
As an alternative embodiment, line 27 can be the nip between a
pair of nip rollers or can represent unrolling of a supply roll
equipped with a constant-height mechanism. If a pair of nip rollers is
used and if a streak of adhesive 29 is deposited on one side before the
film reaches the rolls, the roller contacting this side is grooved to
avoid contact with the adhesive streak.
The sheet of film being pleated leaves line 27 and travels as
a tensioned reach 53 to a line of arrival 37 of composite roll 30.
sheet 50 then passes over surface 31 of composite roll 30 through
angular distance 39 to nip 49 between composite roll 30 and second nip
roller 42 and finally over the second nip roller to leave in the
discharge direction as departing reach 55 which contains a pleat 55.
Instead of passing through nip 49, sheet 50 can leave roll 30
as a reach which extends from pinch zone 38 in the opposite direction
to reach 551 whereby nip roller assembly is not needed. As seen in
Fig. 2, film 50 has edges 52 and I as it passes in the form ox reach
53 from striper roll 20 onto composite roll ED. Reach I is under
selectively varied tension that is represented by vectors 57 and 59 and
moves Saudis, in the direction of vector 59, according to the
guidance provided by the composite peripheral surface of roll 30.
Composite roll 30 is to be understood as rotating on imaginary
axis 33 and as comprising two or more composite rolls having axes of
rotation which are inclined toward each other when viewed as seen in
I
F-0916 -10-
Fig. 2, while rotatively contacting each other along a pinch zone 38
which is close to peripheral surface 31. when viewed at ~0 to the
view of Fig. 29 however, these axes ox rotation always appear as a
straight line.
When two rolls are of approximately equal width, to form a
pleat 5B in the middle of the advancing sheet of film 50, both of the
rolls are preferably inclined with respect in roll I When the rolls
are of unequal width, however, to form a pleat 58 which is near one
edge 52,54 as seen in Fig. 2, it is generally more convenient that the
wider roll be parallel to roll 20.
This configuration is shown in Figs. 2, 77 8, 9 and 109
wherein composite roll 30 comprises a wide roll 60, which is disposed
in parallel to roll 20 and has axis 33 as its axis of rotation, and a
narrow roll 80, having an axis of rotation, which is inclined to the
direction of travel of the sheet ox film when rolls 20,30 are disposed
as seen in Figs. 1 and 2. These two rolls 60,80 are hereinafter
designated for convenience as parallel roll 60 and inclined roll 80.
Rolls 60,80 are inclined to each other at pleat angle 32,
whereby roll 80 has axis of rotation 82 which is inclined by pleat
angle 32 to axis 33 when viewed at 90 to pinch zone 38, as seen in
Fig. 2. Roll 60 has peripheral surface 61, and roll 80 has peripheral
surface 91.
Specifically, as seen in Figs. 1 and 2, composite roll 30
comprises a peripheral surface 31, a parallel roll 60, an inclined roll
80, a pleat angle 32, a pinch zone 38, a shaft 35, and an axis of
rotation 33. The second nip roller assembly 40 comprises a roller 42,
having a peripheral surface 41 and an axis ox rotation 43, and an arm
45 which is pivotal attached at one end to the frame and is rotatable
attached at the other end to a pin at axis 43.
Composite roll 30 can have any diameter that is reasonable and
convenient, such as the same diameter as roll 20, and can be spaced
prom roll 20 at any suitable distance. However, this distance,
illustrated by reach length 34, affects pleating performance.
F-0916
Pleat 58 is wormed from a strip on roll 20 having width 56
which is determined by the Saudis distance that film 50 moves
together while traveling over distance 34 within reach 53 plus the
Saudis distance that the film continues to move together within the
gap after contacting composite roll 30. Figs. 7 and 8 illustrate these
stages of pleat formation. At the preferred wrap around over composite
roll 30 of 90, this width 56 is conveniently expressed in terms of a
right triangle which is clearly seen in Fig 2.
Therefore, when line of arrival 37 is 90 from pinch zone 38
(i.e., angle 39 equals 90), the depth of a pleat 58 is therefore 1~2
of width 56 which can be calculated by the formula: projected distance
17 x tangent of pleat angle 32, wherein projected distance 17 is the
sum of reach length 34 plus the radius of roll 30.
Pleat angle 32 is 0.25 to 5, preferably 1.5. When pleat
angle 32 is small, such as 1.5 or less, there is relatively less edge
distortion of the sheet of film. Edge distortion created by using a
large pleat angle 32, however, can be alleviated by applying heat from
infrared devices along edge 54 and/or strip 56~
If a relatively deep pleat 58 is needed, a larger pleat angle
32, a longer peripheral distance or wrap around distance corresponding
to angle 39, a longer reach 53, or a combination of two or mare owe
these variables, may be utilized. If reach 53 must be as short as
possible, as another example, the same pleat depth can be obtained by
increasing pleat angle 32 and/or increasing the peripheral distance
over surface 31.
This peripheral distance can be varied by changing the
diameter of roll 30 or by changing the amount owe wrap around roll 30,
i.e., angle 39, which is preferably gun but which can vary from 45 to
180~. The greater is angle 39, the shorter can reach 53 ye or the smaller
can be the diameter of composite roll 30, as Embodied by parallel roll
60 and inclined roll 80, to obtain a desired pleating distance.
This strip of film having width 56, as seen in Fig. 29 can be
identified throughout its length along the periphery of roll 20, and at
any convenient place along this length a streak of adhesive 29 can be
-
F-0916 -12~
deposited and selectively solidified before reaching roll 30. As seen
in Figs. 7 and 8, the strip in roll 20 is progressively folded to form
pleat 58 and enclose streak 29.
Instead of streak 29, a cutting or closing device, such as a
piece of drawstring, a piece of cutting string or wire, a flexible tie
strip, or the like can be longitudinally deposited on the strip to be
pleated, preferably in combination with a drop or two of adhesive for
securing the device in place. If desirable to locate one or both ends
of a short piece, such as a flexible tie strip which is disposed within
a pleat 58, one or more portions of the pleat can be excised to expose
one or both ends of the tie strip.
Surface 81 of inclined roll 80 can be the surface of a right
circular cylinder or the surface of the frustum of a right circular
cone so that surface 81 is inclined at bevel angle 89 from the
perpendicular to its circular side 83,85, as seen in Figs. 3, 4, 5, and
6. revel angle 89 can, therefore, vary from 0 to 5 or more and is
preferably selected in accordance with such film characteristics as
tendency to stretch, gage uniformity, evenness of edge 54, and the
like, in order to minimize distortions along edge 54 and pleat 58. In
general, bevel angle 89 is one half of pleat angle 32.
Looking from roll 20 along reach 53 toward roll 30, as in Fig.
39 an observer sees frustum shaped inclined roll I worming a convex
outline (partly in phantom behind roll 20) where line of arrival 37
crosses circularly converging gap 78 between rolls 60,80. At pinch
zone 38, as seen in Fig. 4, surfaces 61,81' form a linear outline.
Guidance of film sheet 50 through the pleating distance is not affected
by this convex relationship of peripheral surfaces blue' at line 37 or
by the linear outline in the vicinity of pinch zone 38; instead such
guidance is effected by the angular relationship of axes 33,82'.
Looking from beyond roll 20 along reach 53 toward roll 30, as
in Fig. 5, an observer sees right cylindrically shaped inclined roll
80" forming a linear outline where line of arrival 37 crosses circular
converging gap 78 between rolls 60,80". At pinch zone 389 as seen in
Fig. 6, surfaces 61,81" from a concave outline Again, however,
F-0916 -13-
directional guidance of film sheet 50 through the pleating distance is
not affected by the linear outline along line ox arrival 37 or the
concave outline in the vicinity of pinch zone 38 and nip 49; it is the
angular relationship between axes 33,~2" that is determining.
Accordingly, if bevel angle 89 is equal to pleat angle 32,
beveled surface 81' is parallel to and aligned with surface 61 only
when at pinch zone 38, as seen at the bottom of Fig. I. At other
angular positions along peripheries 61,~1, as exemplified by beveled
surface 81 on the opposite side of inclined roll 80 as seen in the
middle of Fig. 2, beveled surface 81 is not at all parallel to surface
61 but forms a clearly convex angle therewith.
As particularly shown in Figs. 4, 6, and 9, inclined roll 80
is driven entirely by contact throughout pinch zone 38 along a contact
portion of its inner side surface 85, near its periphery, with a
contact portion of beveled surface 77 of roll 60. Beveled surface 77
is beveled at angle 79, which is generally equal to pleat angle 32,
measured from the perpendicular to surface 61. Surface 77 is divided
into a recess portion having depth 84 and a drive portion having
remaining depth I
The radially measured depth 88 of such contact, as seen in
Fig. 4, is limited by the thickness of cylindrical drum 62 minus the
radially measured depth 84 of the pleat recess having side 83 and width
86 along pinch zone 38. Depth 88 is slightly greater than the depth of
a pleat 58 to be produced within this circumannular recess. The recess
can also be partly cut out of each roll 60,80, as seen in Fig. 8,
wherein inclined roll By has a shallow recess with circumannular side
aye and parallel roll 60 has a matching shallow recess with
circumannular side aye, the total thickness being greater than the
thickness ox pleat 58.
This width 86 between side 83 and surface 77 along pinch zone
38 is principally chosen in accordance with the thickness of the sheet
of film being pleated and is always at least twice as great as the
sheet thickness. In general, it is not desirable to squeeze adhesive
streak 29~ Therefore, width 86 is at least twice the thickness of film
~L~2~l3~L
F-0916 -14-
sheet 50 plus the thickness of film streak 29. Similarly, if a cutting
or closing device, such as a piece of wire or string, is to be enclosed
within pleat 58, thickness 86 is increased to accommodate its
additional thickness.
The patch of movement 57 within reach 53 is parallel to edge
52 as the corresponding portion of the sheet approaches parallel roll
60. However, the portion of sheet 50 approaching inclined roll 80 of
composite roll 30 has an oblique path of movement (as indicated by
vector 59) which is parallel to edge 54 of sheet 50. Inclined roll 80
and parallel roll 60 are inclined at pleat angle 32 to each other and
circularly converge to pinch zone 38 which is 90 away from line of
arrival 37, as seen in Fig. 2.
Parallel roll 60 comprises a cylindrical drum 62 having a
peripheral surface 61, parallel circular sides 63,73, hubs 65,75, a
shaft 71, a key 67 in a kiwi within shaft 71 and hub 65, and a bolt
69 holding key 67 in place. Inner edge 77 of cylindrical drum 62 is
also beveled at angle 79 along its entire circular periphery.
Inclined roll 80 of composite roll 30 is a solidly constructed
annular disc with a large circular opening at its center, comprising a
beveled peripheral surface 81, an inner circular side 85, a
circumferential recess having cir~umannular side I at the outer edge
of its inner side 85, and a stepped cylindrical hub surface 87 for
insertion of bearing assembly 90. This circumferential recess can
alternatively be in inner edge 77 of roll 60 or can be partially cut
into circular sides 77,83 of both rolls 60,80.
Bearing assembly 90 comprises a mounting shaft 91 for inclined
roll I ball bearings 97, an outer race 93 for ball bearings 97, an
inner race 95 for ball bearings 97, a load nut 98 for mounting shaft
91, and a cap housing 99 for outer race 93. Outer race 93 is inserted
into contact with hub surface 87. Load nut 98 thread ably positions
inner race 95 around mounting shaft 91. Cap housing 99 is attached
with four bolts to inner side 85 of inclined roll 80.
~2~3~
F'0916 -15~
The offset or inclined roll bearings are termed
a~gular-contact bearings and are sold as "Fafnir" 720 Series ball
bearings by the Fafnir Bearing Coo New Britain Connecticut. These
are duplex bearings with back-to-back mounting to provide axial and
radial rigidity and equal thrust capacity in either direction when used
in a fixed location.
Hinge mounting assembly 100 is shown in both Figs. 9 and 10.
This assembly comprises a hinged bracket arm 101, a bracket 103 which
is rigidly attached at right angles to arm 101, a hinge 105, and a base
107, hinge 105 being attached to both bracket 103 and base 107. A
spring mounting pedestal lo receives the biasing force 108 of a
compressive sprint having a force of 2 to 20 pounds, preferably 10
pounds, to exert 2 contact pressure of approximately 1 to 10 pounds,
preferably 5 pounds, along the portion within pinch zone I of the
annular strip of surface 85 having width By, to effectuate driving
contact with surface 77 of roll 60.
Composite roll 30 can be expanded from a two-piece roil to a
multi-piece roll 100 having an axis of rotation 113, as seen in Fig.
11, which comprises a parallel roll 60, a pair of primary inclined
rolls 111, and a pair of secondary inclined rolls 113. Strips 116
which are formed over roll 20 move together while entering circularly
converging gaps 115 between rolls 60,111 and between rolls 111,113 to
form pleats 118 within pinch zones 117, as seen in Fig. 12. Secondary
rolls 112 are necessarily smaller than primary rolls 111 if these rolls
are shaped as the frustum of a cone.
A plurality of pleats 118 are practicable for repeated sealing
of bags and the like when dusty conditions destroy the usefulness of an
adhesive streak after one use thereof. They are also helpful when one
pleat can be feelingly opened for sealing purposes and another pleat
can be aggressively sealed (as when two streaks of adhesive are placed
in contact) and utilized for holding a drawstring or metal tie for
closing purposes or for holding a cutting wire, for example, or
opening purposes.
*Trademark
.. . .. .. . . .
F-0916 -16-
Moreover, two apparatuses of this invention can be combined in
series to form one or more pleats on each side of a sheet of film, by
reversing the direction in which the striper roll and the two-piece or
multi-piece roll rotate for each apparatus. The pleat which is thereby
wormed on the inside of a bag can be of substantial width, and by
bringing together opposed streaks of adhesive, a very strong and
effective interior seal can be obtained. Thereafter, the pleat which
is thereby formed on the exterior of the bag can be used to close a
protective flap, as in a sandwich bag, or to provide a vie as a back-up
closing means or to provide a cutting tool in the form of a wire or
monofilament. Such a combination is particularly helpful under field
conditions for large bags when a hot-melt sealing machine is not
available.
Manufacturing two-pleat trash bags is described in the
following illustrative example and in Fig. 13. Usage of the folds or
pleats of Fig. 13 is illustrated in the accompanying Fig. 14.
A two-pleat strip-folding apparatus of the invention is set up
for forming two closely spaced pleat on the same side of a
continuously advancing sheet of indeterminate length. A supply of
Molly. polyethylene film is arranged to pass over the single
two-pleat apparatus (arranged as on the left side of apparatus 110 in
Fig. 11), forming two continuous and relatively large pleats 131,137,
and then on two a winder. The wound roll is subsequently unwound onto
a transverse cutting means which separates the pleated film into a
large plurality of transversely extending strips which then move at 90
to a molding apparatus and finally to an edge sealing apparatus,
forming a plurality of trash bags 120 having the sectional
configuration shown in Fig. 13. The pleats and portions of this bag
120 are referred to hereinafter while describing the pleating
operations.
At first pleat 131 begins to be formed on the striper roll, a
streak of adhesive 133 is added along one outer edge only. Streak 133
is narrow, very aggressive and highly viscous, so that it spreads very
little, even though not prickled, while passing through the pinch
F-0916 -17-
zone. A continuous length of drawstring 135 is then laid in the center
ox pleat 131 without substantial contact with adhesive 133.
Preferably, however, there is sufficient contact with the adhesive that
the drawstring will not slip endues out the pleat prior to use but can
be broken free by a moderate pull during use thereof.
As a second strip be my to be folded while passing over the
striper roll for making attachment pleat 137, a streak of adhesive 139
is deposited thereon in the same manner as streak 29, as shown in Fig.
2. Adhesive streak 139 is substantially prickled before passing
through the pinch zone.
Aster the pleated film has passed through the cutting
operation, the transverse moving operation, and the edge sealing
operation bags 120 are formed, each having folded bottom edge 125,
sides 121, top edge 1299 and two pleats 131,137 which are both on the
inside of the bag. When the side edges are cut, drawstring 135 is also
severed. However, its ends are easily accessible because pleat 131 is
wide enough to insert fingers for grasping the cut ends of drawstring
135.
These pleats are utilized as shown in Fig. 14 in combination
with a trash receptacle 140 having bottom 141, sides 143, and top edge
145. Beginning at the top of bag 120, pleat 1~7 is snapped open, after
bug 120 has been inserted into trash receptacle 140, and adhesive
streak 13g is pressed against sides 143, near top edge 145 ox the
receptacle/ so that bag 12U does not fall down inside the receptacle.
After bag 120 has become substantially filled with trash,
adhesive streak 139 is pulled away from sides 143 and pressed against
adjacent portions of side 121, essentially reforming pleat 137 in order
to obviate sticking to the user's hands.
Pleat 131 is then utilized by pulling upon the exposed ends of
drawstring 135 and tying drawstring 135, whereby the filled bag 120 is
suitable for immediate disposal.
After testing, it is found that bag 120 has a distinct
handling advantage, with respect to closing when nearly filled, over
bags of the prior art which require one hand to be used for squeezing
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toe topmost few inches of a nearly filled bag while the other hand
makes a desperate attempt to secure a tie strip around the slippery
film Moreover, bag 120 can contain a larger amount of trash than the
prior art bags because its upper portion need not be compressed as much
as these bags in order to shorten its drawstring 135 sufficiently to
effectuate closure thereof.
. . .
