U.S. patent application number 15/804237 was filed with the patent office on 2018-03-01 for elastic break brake apparatus and method for minimizing broken elastic rethreading.
This patent application is currently assigned to Curt G. Joa, In.. The applicant listed for this patent is Curt G.Joa, Inc.. Invention is credited to Jeffrey W. Fritz, John A. McCabe, Christopher J. Nelson, Daniel A. Peterson.
Application Number | 20180057304 15/804237 |
Document ID | / |
Family ID | 48145524 |
Filed Date | 2018-03-01 |
United States Patent
Application |
20180057304 |
Kind Code |
A1 |
Fritz; Jeffrey W. ; et
al. |
March 1, 2018 |
ELASTIC BREAK BRAKE APPARATUS AND METHOD FOR MINIMIZING BROKEN
ELASTIC RETHREADING
Abstract
A series of elastic break brakes are provided throughout a
travel path of elastics in a machine operation. Elastic strands
thread through each individual brake mechanism, and if an elastic
strand breaks downstream, a natural snap back of the elastic, which
ordinarily travels through the system under tension, drives an
immediately upstream cam mechanism back, and holds the elastic
thread in place at the elastic break brake immediately upstream of
the break as to minimize rethreading required downstream of the
elastic break brake.
Inventors: |
Fritz; Jeffrey W.;
(Plymouth, WI) ; Nelson; Christopher J.;
(Plymouth, WI) ; McCabe; John A.; (Sheboygan
Falls, WI) ; Peterson; Daniel A.; (Sheboygan,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Curt G.Joa, Inc. |
Sheboygan Falls |
WI |
US |
|
|
Assignee: |
Curt G. Joa, In.
Sheboygan Falls
WI
|
Family ID: |
48145524 |
Appl. No.: |
15/804237 |
Filed: |
November 6, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13868712 |
Apr 23, 2013 |
9809414 |
|
|
15804237 |
|
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|
61637365 |
Apr 24, 2012 |
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61645867 |
May 11, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2701/194 20130101;
B65H 57/14 20130101; A61F 2013/1591 20130101; A61F 13/49017
20130101; A61F 13/49019 20130101; A61F 13/15804 20130101; A61F
13/15601 20130101; B65H 63/024 20130101; A61F 13/15593 20130101;
B65H 20/02 20130101; B65H 35/0086 20130101 |
International
Class: |
B65H 57/14 20060101
B65H057/14; A61F 13/15 20060101 A61F013/15; B65H 63/024 20060101
B65H063/024 |
Claims
1. A method of controlling an elastic thread comprising the steps
of: providing an elastic break brake, said elastic break brake
comprising a base, a base back depending from said base, a pin
coupled to said base back said pin having an axis of rotation, and
a rotating cam weight carried by said pin and rotatable coaxially
with said axis of rotation; a base elastic retaining surface spaced
apart from said rotating cam weight; a nip point between said base
elastic retaining surface and said rotating cam weight, said pin
vertically aligned with said nip point; moving said elastic thread
in a downstream direction; rotating said rotating cam weight in a
downstream machine direction by elastic traveling under tension
between said rotating cam weight and said base elastic retaining
surface; allowing passage of said elastic during machine operation;
rotating said rotating cam weight in an upstream direction upon
breakage of said elastic thread; and cinching said elastic thread
between said rotating cam weight and said base elastic retaining
surface thereby stopping said elastic.
Description
RELATED APPLICATIONS
[0001] This application is a division of co-pending U.S. patent
application Ser. No. 13/868,712, filed 23 Apr. 2013, which claims
the benefit of U.S. Provisional Patent Application Ser. Nos.
61/637,365, filed 24 Apr. 2012, and 61/645,867, filed 11 May
2012.
BACKGROUND OF THE INVENTION
[0002] The invention relates to disposable garments, and more
particularly, a pants-type diaper, which is equipped with elastic
strips effectively encircling the leg-holes without traversing the
crotch region and to a method for producing such diapers.
[0003] Disposable diapers of the children's training pant type, or
of the adult incontinence type, are typically equipped with elastic
strands, which encircle the leg-holes. These strands of elastic are
typically captured with adhesive between two layers of non-woven
materials. Various methods are used to position these elastic
strands so that they produce the desired encircling effect.
[0004] In one method of manufacture, the diapers are produced in an
orientation whereby product flow is in the form of a single
continuous web and the direction of travel is at a right angle with
respect to what would be described as the crotch line of the
diaper, i.e., the normal direction of product flow is parallel to
the waist as opposed to parallel to the crotch.
[0005] One method of creating the desired effect of encircling the
leg holes of the pant with elastics is to interleave two swaths of
elastic strands, each curving across the face of the traveling web,
encircling about one half of the leg-hole areas and crossing the
path of the other. As a pair, they create a boundary around each
leg-hole cutout, which resembles a circle or ellipse. In practice,
however, the lateral excursions of the elastic lay-down device are
speed-limited. As the traveling web is moving at some speed in one
direction, and as the elastic lay-down device has speed and
acceleration limits in the cross-direction, there is a limit to the
steepness of the oblique angle which it is possible to form between
the two. The result of this limitation is usually seen in the form
of apparent incompleteness in the formation of the
leg-hole-encircling pattern, particularly at the crotch line, where
the two swaths cross each other.
[0006] From the point on the web at which one leg-hole pattern has
been completed to the point at which the next can be begun, the
elastic laydown device must reposition itself to a favorable
starting point. This period of repositioning occurs as the crotch
region passes the laydown device. As a result, the elastic strands
must also cross this region of the product, at which they may or
may not be attached by means of adhesives to the carrier webs.
Various means are used to control or limit the positional
relationships of the elastic strands in this region. The two sets
of strands may cross over each other, creating an "X" pattern, or,
they may loop back over to their respective sides, creating an "O"
at the center of the crotch region. Alternatively, they may be
mechanically stopped and prevented from crossing each other,
creating two sets of generally parallel lines at the crotch. The
lay-down pattern used at the crotch will determine the final
appearance of the product in this area.
[0007] The shirring effect created by elastic strands when
laminated with any flexible fabric is well known. However, to have
this shirring effect applied to the crotch of a pant-type garment
can be undesirable. The elastics create a contractile force, which
tends to distort the garment at this location, thereby reducing the
garment's aesthetic appeal, effectiveness and comfort. Thus various
methods of reducing or eliminating the effects of the elastic
tension normally occurring at the crotch have been attempted. These
methods include the elimination of the adhesive bond between the
strands and the liner materials described in U.S. Pat. No.
5,745,922 as "unsecured space" as well as various methods of
cutting the strands to eliminate their effects.
[0008] As mentioned, one method of eliminating the undesired
effects of the elastic strands which cross the crotch region is to
sever them. This method is described in U.S. Pat. No. 5,660,657.
Unfortunately, such severing usually requires the introduction of a
transversely extending cut, which can result in a loss of web
tension in the severed part of the carrier web. This also creates
an undesirable opening in the diaper backsheet. A proposed solution
for this problem is taught in U.S. Pat. No. 5,707,470, wherein an
ultrasonic device is used to sever the elastic members, while the
carrier webs which encapsulate the elastics are left intact. See,
also, U.S. Pat. No. 5,643,396. Another problem associated with such
severing lies in the tendency of the unsecured severed ends of
elastic to retract to some point beyond the limits of any adhesive
pattern. Thus, the elastic strands are not controlled or anchored
near the ends of the adhesion pattern and may snap back to further
into the adhesive pattern. This results in an incomplete elastic
pattern and poor product characteristics.
[0009] One method of compensating for the incompleteness of the
encircling pattern entails insertion of an additional set of
elastic strips, running parallel to the crotch line and transverse
to the web path. See U.S. Pat. Nos. 5,634,917 and 5, 660,657.
Typical products of this type are provided with an outer laminate,
which is formed of an inner liner material and an outer backsheet
material, between which the leg-hole elastics are disposed.
[0010] Often, leg elastics or other types of continuous ribbons are
applied to running webs in a sinusoidal pattern by a roll-fed web
process. Roll-fed web processes typically use a constant infeed
rate, which in the case of a sinusoidal ribbon application, can
result in necking, or undesirable narrowing of the ribbon toward
the inner and outer portions of the sine curve in the cross-machine
direction. This is because the infeed rate of the ribbon web does
not match with the velocity of the substrate it is being laid upon
in the machine direction. Instead, the ribbon material is stretched
somewhat at the extremities of the sine curve.
[0011] Roll-fed web processes typically use splicers and
accumulators to assist in providing continuous webs during web
processing operations. A first web is fed from a supply wheel (the
expiring roll) into the manufacturing process. As the material from
the expiring roll is depleted, it is necessary to splice the
leading edge of a second web from a standby roll to the first web
on the expiring roll in a manner that will not cause interruption
of the web supply to a web consuming or utilizing device.
[0012] In a splicing system, a web accumulation dancer system may
be employed, in which an accumulator collects a substantial length
of the first web. By using an accumulator, the material being fed
into the process can continue, yet the trailing end of the material
can be stopped or slowed for a short time interval so that it can
be spliced to leading edge of the new supply roll. The leading
portion of the expiring roll remains supplied continuously to the
web-utilizing device. The accumulator continues to feed the web
utilization process while the expiring roll is stopped and the new
web on a standby roll can be spliced to the end of the expiring
roll.
[0013] In this manner, the device has a constant web supply being
paid out from the accumulator, while the stopped web material in
the accumulator can be spliced to the standby roll. Examples of web
accumulators include that disclosed in U.S. patent application Ser.
No. 11/110,616 (US2005/0230449), which is commonly owned by the
assignee of the present application, and incorporated herein by
reference.
[0014] Examples of curved elastic application are disclosed in U.S.
Pat. No. 6,482,278, incorporated herein by reference. Other
examples include U.S. Pat. Nos. 8,100,173 and 8,025,652.
[0015] During the use of elastics in manufacturing disposable
products, a continuous web of elastic is often threaded through
numerous pieces of machinery upstream of a deposition point and
adhesion of the elastic to another running web, such as a nonwoven
material. If for some reason an elastic strand breaks during
machine operation, it is necessary to re-thread the elastic through
all of the machinery both upstream and downstream of the break.
SUMMARY OF THE INVENTION
[0016] Provided are methods and an apparatus for applying parallel
flared elastics to a substrate used to form a disposable product,
and severing elastics contained in a laminate from a leg hole
opening. Other novel laydown patterns of elastics are also
disclosed.
[0017] A series of elastic break brakes are provided throughout a
travel path of elastics in a machine operation. Elastic strands
thread through each individual brake mechanism, and if an elastic
strand breaks downstream, a natural snap back of the elastic, which
ordinarily travels through the system under tension, drives an
immediately upstream cam mechanism back, and holds the elastic
thread in place at the elastic break brake immediately upstream of
the break as to minimize rethreading required downstream of the
elastic break brake.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1a-1c, collectively, are perspective views showing a
preferred embodiment of the invention in somewhat diagrammatic
fashion;
[0019] FIG. 2 is a diagrammatic view of the equipment and process
shown in FIGS. 1a-1c;
[0020] FIGS. 3a-3b are, collectively, a perspective view showing in
somewhat diagrammatic fashion an alternative embodiment of the
invention;
[0021] FIG. 4 is a diagrammatic view further illustrating the
process and equipment shown in FIGS. 3a-3b;
[0022] FIG. 5 is a top plan view of a ribbon application sequence
of the present invention;
[0023] FIG. 6 is a top view of an exemplary pair of swinging arms
for applying elastic in a wave (or other) pattern on a running
web;
[0024] FIG. 7 is a perspective view showing a preferred embodiment
of the invention in somewhat diagrammatic fashion, used to create a
pant-type diaper with waist band elastics and parallel flared
elastics, with a portion of the curved elastics removed by a chip
in a leg opening section of the pant-type diaper;
[0025] FIG. 8 is a plan view of a pant-type diaper with waist band
elastics and curved elastics, with a portion of the curved elastics
removed by a chip in a leg opening section of the pant-type diaper
prior to bonding a front, portion of the diaper with a rear (or
back) portion of the diaper;
[0026] FIG. 9 is a plan view of a portion of a pant-type diaper
showing a side seam bond between and front and a rear portion of
the diaper, showing parallel flared elastics extending to a die cut
leg cutout area, where the parallel flared elastics are
removed;
[0027] FIGS. 10-12 are in-process top views of pant type diapers
with varying applications of straight and curved elastics;
[0028] FIG. 13 is a perspective view showing in somewhat
diagrammatic fashion an application of the elastic break brake
invention, with a series of elastic break brakes applied throughout
the travel path of introduced elastic webs;
[0029] FIG. 14 is a side view of elastic break brakes of the
present invention, carrying an elastic strand between a rotating
cam and a base;
[0030] FIG. 15 is a side view of a series of elastic break brakes
of the present invention, carrying an elastic strand;
[0031] FIG. 16 is a side view of elastic break brakes of the
present invention, carrying an elastic strand between a rotating
cam and a base, with a break in the elastic strand upstream of a
series of the elastic break brakes, the elastic break brake
immediately upstream of the break rotating counterclockwise to
cinch the elastic strand between the rotating cam and the base and
holding the elastic strand such that only re-threading downstream
of this elastic break brake is required;
[0032] FIG. 17 is a side view similar to FIG. 16, with a break in
the elastic strand between two elastic break brakes, the elastic
break brake immediately upstream of the break rotating
counterclockwise to cinch the elastic strand between the rotating
cam and the base and holding the elastic strand such that only
re-threading downstream of the first elastic break brake is
required;
[0033] FIGS. 18-23 are top views of pant type diapers with varying
applications of straight and parallel flared elastics.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Although the disclosure hereof is detailed and exact to
enable those skilled in the art to practice the invention, the
physical embodiments herein disclosed merely exemplify the
invention which may be embodied in other specific structures. While
the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by
the claims.
[0035] Referring first to FIGS. 1a, 1b and 1c, one of the preferred
embodiments of the process of this invention and related apparatus
are illustrated. The process utilizes two main carrier webs; a
non-woven web 11 which forms an inner liner web, while web 12 forms
an outwardly facing layer in the finished diaper. In this
embodiment, non-woven web 11 is slit, at slitter station 15, by
rotary knives 14 along three lines. One of these, line 16, is on
approximately the centerline of web 11 and two additional lines 17
and 18 are parallel to and spaced a short distance from centerline
16. The effect is twofold, first, to separate web 11 into two
halves, as also seen in FIG. 5b. One half, 19, will become the
inside of the front of the diaper 50 and the second half, 20, will
become the inside of the back of that garment. Second, two
separate, relatively narrow strips 22 and 24 are formed which are
subsequently used to cover and entrap portions of the leg-hole
elastics 25 and 26. Strips 22 and 24 are separated physically by an
angularly disposed spreader roll 23 and aligned laterally with
their downstream target positions on the inner edges of webs 19 and
20.
[0036] This invention relates particularly to a variation in the
way that leg elastics 25 and 26 (which can be ribbons) are applied.
In particular, the infeed rate of leg elastics or ribbons 25 and 26
is sped up at the outer extremities of the sine curve in the
machine direction so that the vertical component of the velocity of
the ribbon placement is at or near the velocity of the substrate
web 20 to which the ribbon is applied. This results in little to no
tension upon the elastics or ribbons 25 and 26.
[0037] Adhesive patterns are applied to the liner webs 20 in target
areas for the leg-hole elastics 26. A spray gun assembly 29 of a
type known in the art is preferably used to apply the adhesive
patterns. Two sets of leg-hole, elastic strands 26 are introduced
through laydown guides 30, which reciprocate from side to side past
each other. The strands 26 are glued to the web sections 20, their
laydown patterns following a serpentine or sinusoidal path. Laydown
guides 30 then apply the strands 26, which form leg-hole elastics
as the web sections 20 are carried along the face of a drum or roll
32.
[0038] In a preferred embodiment of the present invention, the
elastics 25 and 26 are laid down in a smooth repetitive
oscillation, with a centerline along an line in the machine, and an
amplitude in the cross-machine direction. In a preferred
embodiment, the infeed velocity of the elastics is increased as the
waveform reaches maximum amplitude, then decreases again until the
laydown passes the centerline, increasing again until minimum
amplitude. This variation decreases neckdown.
[0039] Elastic laydown guides 28 and 30 are provided with the
ability to make side-to side excursions, and the infeed of elastic
25 and 26 is provided with the ability of variable infeed speed.
Elastic laydown guides 28 and 30 can be provided with the ability
to make side-to side excursions by an arm that generally travels
side to side e.g., by a swinging motion, or slides side to side.
The side-to-side excursions of the leg-hole elastic laydown guides
28 and 30 result in generally arcuate segments of elastic strands
extending on each side of the web centerline. After the nonwoven
strips 22 and 24 have been applied to cover and entrap those parts
of the elastics 26 that run nearest to and parallel to the inner
edges of the webs 20, a second pair of slitter knives 34 is used to
trim away a portion of the narrow nonwoven strips 22, 24, along
with that part of the inner liner webs 20 to which they are
laminated. This also removes those portions of the elastic strands
26 which are contained within the laminations. The resultant
trimmed scrap strips 36 are removed from the process for disposal
elsewhere.
[0040] The effect of the last-described step is to remove the cut
away portions of the elastic, eliminating its corresponding
unwanted gathering effect from the crotch region of the garments
50. The remaining portions of the curved elastic strands create a
gathering effect around the leg openings of the finished garments
50.
[0041] Subsequent to the combining and trimming of the inner webs
20 and the cover strips 22, 24, the combining drum 32 carries the
webs to a nip with a second combining drum 38, where the web
sections 20, with their respective curved elastic patterns exposed,
are transferred to and laminated adhesively against the inside face
of outer liner web 12. This process entraps the curved elastic
patterns 26 between the inner liners 20 and outer web 12 thereby
forming a composite web 39.
[0042] The composite web 39 is then provided with a pattern of
adhesive in preparation to receive an absorbent insert or patch 46.
The patch 46 is cut from a provided patch web 40 by a cooperation
of a cutter 41 and an anvil surface on a vacuum roll 42 and rotated
into position for transfer to the composite web 39 by a patch
applicator 105. If the patch 46 is to be applied to the web 39, a
determination explained more fully below, the patch applicator 105
forces the web 39 against the patch 46, thereby adhering the patch
46 to the web 39.
[0043] Leg-hole materials 48, if not previously removed, are cut at
a cutting station 47, thereby removing the material 48 contained
within an approximate perimeter defined by the curved pattern of
the elastics 26 and defining one half of a leg opening (with the
other half of a leg opening provided in an adjacent leg-hole
opening). The running composite chassis web 39 is folded, before or
after cutting out of the leg holes, longitudinally along its
centerline, thereby generally aligning its front waist edge with
its back waist edge. The regions 53 which are to become the side
seams 54 of the garments 50 are then wielded by a sealing device 49
either ultrasonically or by heat. Note that the leg holes are
preferably cut out before this point, leaving only a narrow zone
for welding. The weld pattern is preferably wide enough to extend
into both the left side seam of one garment and the right side seam
of the adjacent garment. The garments 50 are then separated by
passing through a cut-off knife assembly 55, which severs the web
along the transverse axis of the side seam weld 53.
[0044] As described above, the laydown guides 30 used to apply the
leg-hole elastics 26 to the liner web 20 oscillate from side to
side to apply the leg-hole elastic 26 to the liner web 20 in a
generally wave-like pattern. It should be understood that due to
the oscillating motion of the laydown guides 28 and 30, it is
desirable to change the rate at which the leg-hole elastic 25 and
26 is introduced to the liner web 20. As shown in FIG. 5, the
velocity of the leg-hole elastic 26 has both a vertical (machine
direction) component Vy and a horizontal (cross-machine direction)
component Vx. It is contemplated that the vertical component of the
velocity of the leg-hole elastic 25 and 26 is equal to, and in the
same direction as, the velocity of the liner web 20 on which the
leg-hole elastic 26 is being applied.
[0045] The incoming ribbon has variable speed, with the incoming
ribbon increasing in velocity as the incoming ribbon is deposited
in the curved pattern from the centerline to the maximum amplitude
(its greatest distance from the centerline in the cross-machine
direction towards a first boundary of the web), decreasing as the
incoming ribbon is deposited in the curved pattern from the maximum
amplitude to the centerline, and increasing as the incoming ribbon
is deposited in the curved pattern from the centerline to the
minimum amplitude (its greatest distance from the centerline in the
cross-machine direction towards the other boundary of the web).
[0046] In a preferred elastic laydown pattern such as shown in FIG.
5, two lanes of elastic 25 and 26 are laid down in separate lanes,
with both minimum amplitudes in the same position in the machine
direction.
[0047] At least one web accumulator (not shown) can be located
upstream of, or before, the leg-hole elastic guides 30, as shown in
FIG. 1a. The accumulator can take any form, such as a servo driven
roller that speeds up and slows down, an alternate roller
configuration, a rocking roller configuration, or any different
means of accumulating the web, such as a miniature accumulator, or
a device similar to a diaper cross-folder, or a tucker
[0048] In this manner, the rate at which the leg-hole elastics 26
are being fed to the liner web 20 can be altered while the rate at
which the leg-hole elastics 26 is fed to a rate adjustment
apparatus 314 (not shown) remains the same.
[0049] It is further contemplated that the system may include a
tension control device (not shown). The tension control device is
preferably sized and configured to eliminate tension in the
leg-hole elastic 26 prior to applying the leg-hole elastic 26 to
the liner web 20. In this manner when the leg-hole elastic 26 is
applied to the liner web 20, the leg-hole elastic will not become
misshapen as it would if the leg-hole elastic 26 were under
tension. The tension control device can takes the form of a web
accumulator, or any form known in the art capable of performing
such a function.
[0050] In this manner, the leg-hole elastic 26 is accumulated in
the tension control device when the rate of application of the
leg-hole elastics 26 to the liner web 20 is slowed as described
above. It is contemplated that the above-described system will
provide active tension control and feed approach to change the feed
of the leg-hole elastics 26 to the liner web 20 so that the
leg-hole elastic is not under tension when it is applied to the
liner web 20. This will result in leg-hole elastics 26 that are
applied to the liner web 20 in an undistorted manner.
[0051] Referring now to FIG. 6, a top view of an exemplary pair of
swinging arms 90 for applying elastics 25 and 26 is shown. The
swinging arms can be programmed or operated to apply the elastics
in a wave pattern (see, e.g., FIG. 5) on a running web such as
shown in FIG. 1.
[0052] It should be understood that the above-described arrangement
may be used to apply any type of material to a moving web in a
curved pattern. In the illustrated example, the material is
leg-hole elastics 26 taking the form of elastic strands; however it
is contemplated that the material could take the form of elastic
tape. It is further contemplated that the material could take the
form of non-elastic strands or non-elastic tape.
[0053] Referring now to FIG. 7, a perspective view showing a
preferred embodiment of an alternative embodiment of the present
invention is shown. This embodiment is used to create a pant-type
diaper with waist band elastics and curved elastics, with a portion
of the curved elastics removed by a chip in a leg opening section
of the pant-type diaper.
[0054] In this embodiment, two or more series of leg band elastics
210 and 212 are laid down. Preferably waistband elastics 210 run
parallel to one another, while another sequence of leg and waist
elastics 212 are laid down in a curved pattern inboard of the
waistband elastics 210. Preferably, the leg and waist elastics 212
are applied in a curved fashion. At what will become the leg hole
opening of the diaper, the leg and waist elastics 212 are generally
parallel, and each of the independent the leg and waist elastics
212 are then curved towards absorbent insert or patch 46, and
increasingly separated in distance from one another the closer the
leg and waist elastics 212 get to the absorbent insert or patch
46.
[0055] As described above, sliding laydown guides 30 can be used to
apply the leg and waist elastics 212 to the liner web 20, the
laydown guides oscillates from side to side to apply the leg and
waist elastics 212 to the liner web 20 in a generally wave-like
pattern. Alternatively, a swing arm or series of swing arms 90 such
as shown in FIG. 6 can be used to apply the leg and waist elastics
212. The swing arms 28 and 30, or the sliding layding guides 30 can
be programmed to move in a predetermined fashion in order to lay
down a straight line of elastics 26 in a machine direction by
remaining in a constant position, or can lay down a patterned shape
of elastics 26 by moving from side to side as desired.
[0056] Referring now to FIGS. 8 and 9, plan views of a pant-type
diaper with parallel waist band elastics 210 and flared leg and
waist elastics 212 is shown.
[0057] Similar to the configuration shown in FIG. 1b, leg-hole
materials 48, if not previously removed, are cut at a cutting
station 47 (FIG. 7), thereby removing the material 48 and forming a
leg opening contour 216 on both the left and the right sides of the
product. Referring particularly to FIG. 9, it can be seen that the
leg and waist elastics 212 do not occupy what later will become
seam 53, but instead pass through leg opening contours 216 for
removal at cutting station 47 (FIG. 7).
[0058] Referring now to FIGS. 10-12, these FIGS. show in-process
top views of pant type diapers with varying applications of
straight and curved elastics.
[0059] As shown in FIG. 10, in one embodiment, parallel waist
elastics 210 are applied to both the front and the back, and a
series of parallel leg and waist elastics 212 are provided on a
front of the product, while curved leg and waist elastics 212 are
provided on the rear of the product. The curved leg and waist
elastics 212 of the rear of the product would cross a secondary leg
contour 216 of the product, and those elastics would not be
contained within the side seam bond 53.
[0060] Referring to FIG. 11, parallel waist elastics 210 are
applied to both the front and the back, and a series of parallel
leg and waist elastics 212 are provided on a front of the product,
while curved leg and waist elastics 212 are provided on the rear of
the product. The curved leg and waist elastics 212 of the rear of
the product would cross a secondary leg contour 216 of the product,
and those elastics would not be contained within the side seats
bond 53. Similarly, a portion of the parallel leg and waist
elastics 212 of the front of the product would enter a tertiary leg
contour 216, and some of those parallel leg and waist elastics 212
would be severed during chip removal.
[0061] In the embodiment shewn in FIG. 12, curved leg and waist
elastics 220 are provided on the front of the product, and curved
leg and waist elastics 212 which do not enter the side seams 53 are
provided on the rear of the product. These and other elastic lay
down variations, including following the leg cut in a tight group,
a combination of a flared feature on the back (or front); and the
opposing sides with elastics are tightly grouped together following
a leg cut die and going through the leg cut die; or no elastics in
those portions, are all contemplated.
[0062] Referring now to FIGS. 13-16 generally, a series of elastic
break brakes 300 are provided throughout a travel path of elastics
(such as elastic 26) in a machine operation. Elastic strands thread
through each individual brake mechanism 300, and if an elastic
strand breaks downstream, a natural snap back of the elastic, which
ordinarily travels through the system under tension, drives an
immediately upstream cam mechanism back, and holds the elastic
thread in place at the elastic break brake 300 immediately upstream
of the break as to minimize rethreading required downstream of the
elastic break brake.
[0063] Referring generally to FIGS. 13-17, an elastic break brake
300 to allow downstream travel of an elastic thread during machine
operation and to stop unwanted elastic travel is disclosed. A
rotating weight 310 is carried by a pin 308 coupled to a base 306.
A base elastic retaining surface 312 spaced apart from said
rotating cam weight 310. The rotating cam weight 310 is rotatable
by the force of elastic 26 traveling under tension between said
rotating cam weight 310 and said base elastic retaining surface
312. The force of the traveling elastic 26 causes the cam weight
310 to be slightly rotated in a downstream machine direction
allowing passage of said elastic 26 during machine operation. If a
break in the elastic 26 occurs, the elastic goes limp and therefore
the force of the traveling elastic 26 is no longer enough to hold
the rotating cam weight 310 in its slightly downstream rotated
position. Instead, the cam weight 310 rotates back upstream due to
gravity and the absence of the force from elastic 26 traveling
under tension. The elastic 26 is then trapped between the cam
weight 310 and the elastic retaining surface 312. This prevents
unwanted elastic 26 travel, and makes the task of re-threading the
elastic 26 far shorter.
[0064] Referring now to FIG. 13, a perspective view of a
representative elastic travel sequence is shown in somewhat
diagrammatic fashion. A series of elastic break brakes 300 are
provided throughout the travel path of introduced elastic webs, and
through each elastic break brake 300, the continuous web of elastic
is threaded.
[0065] Referring to FIG. 14, a side view of elastic break brakes
300 of the present invention are shown carrying an elastic strand
26. A securing mechanism(s) 304 holds the elastic break brakes 300
in place. The elastic is threaded between a rotating cam weight 310
and a base elastic retaining surface 312, which is very closely
spaced apart from the rotating cam weight 310. The rotating cam
weight 310 is carried by pin 308 coupled to a base back 306
generally depending from base 302.
[0066] During routine operation, the elastic 26 is traveling under
tension, and at speed, sufficient to cause the cam weight 310 to be
slightly rotated in the downstream (machine) direction. Elastic 26
is allowed to and capable of passing between the cam weight 310 and
the base elastic retaining surface 312.
[0067] Referring now to FIG. 15, should a break in the elastic
strand 26 occur upstream of a series of the elastic break brakes
300, the elastic break brake immediately upstream of the break in
the elastic would, due to gravity or otherwise (e.g., a spring
mechanism, or motor controlled) rotate counterclockwise to cinch
the elastic strand 26 between the cam weight 310 and the base
elastic retaining surface 312. By maintaining control of the
elastic 26 just upstream of the break point of the elastic 26, only
re-threading downstream of the activated elastic break brake 300 is
required.
[0068] Similarly, as shown in FIG. 16, should a break in the
elastic strand 26 occur between two elastic break brakes 300, the
elastic break brake 300 immediately upstream of the break would due
to gravity or otherwise (e.g., controlled) rotate counterclockwise
to cinch the elastic strand 26 between the cam weight 310 and the
base elastic retaining surface 312. By maintaining control of the
elastic 26 just upstream of the break point of the elastic 26, only
re-threading downstream (in the machine direction) of the activated
elastic break brake 300 would be required.
[0069] Referring new to FIGS. 18-23, top views of pant type drapers
with varying applications of straight and curved elastics are
shown.
[0070] Referring to FIG. 18, a series of flared elastics 400 are
provided on a front and a back of a pant type diaper. On the back
side, a single straight elastic strand 402 is provided, which is
crossed over by the flaring elastics 400 of the back side of the
pant.
[0071] In FIG. 19, multiple straight elastic strands 402 are
provided on the rear of the diaper, which are crossed over by the
flaring elastics 400.
[0072] Referring to FIG. 20, another novel elastic laydown pattern
is shown. In this embodiment, the distance between successive
strands of the flared elastics 400 on the rear side decreases
towards the center of the diaper. A similar embodiment is shown in
FIG. 21, but the flaring elastics 400 on the rear stop well short
of a centerline CL of the product and are discontinued across the
crotch portion of the product.
[0073] Referring to FIGS. 22 and 23, the elastics 400 do not fan,
but instead are parallel to one another generally along a leg
cutout 216, and then run parallel to each other through the
centerline CL of the product. This configuration is a flared
configuration. In this arrangement, the elastics 400 run from near
the disposable product side areas 410 (when worn about the waist of
a user) and run parallel from there, toward the crotch portion of
the diaper, and particularly toward the absorbent core 46 crossing
the centerline CL. In this sense, the elastics 400 generally are
running in a direction that is skew to the machine direction. Each
of the elastics 400 eventually turns to the centerline CL and next
runs in the machine direction for a segment. At the centerline.
Throughout the elastic laydown sequence, elastics 400 will be
parallel, but spaced apart based on the time the elastic departs
from the generally parallel to the leg cutout 216 direction, to the
machine direction. At the parallel to the leg cutout 216 direction,
the plurality of elastic strands 400 are considered running in
parallel skew to the machine direction, that is neither in the
machine direction or the cross machine direction. Still running in
parallel, the elastic 400 pattern is mirrored, and the elastics
return the flare to a second side area 410 of the product,
resulting in a parallel flared elastic pattern. Additionally, at
least one of the front or back set of elastics 400 could run
entirely curved and parallel along their traverse of the front or
back panel.
[0074] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the claims.
* * * * *