U.S. patent application number 09/896049 was filed with the patent office on 2002-02-28 for stretch cushion strap assembly and method and device for making same.
This patent application is currently assigned to Playtex Apparel, Inc.. Invention is credited to Falla, Gloria, Paschal, P. Benjamin, Petrovich, Joseph M., Poindexter, Billy II, Tedeschi, Anthony J..
Application Number | 20020023709 09/896049 |
Document ID | / |
Family ID | 23024539 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020023709 |
Kind Code |
A1 |
Tedeschi, Anthony J. ; et
al. |
February 28, 2002 |
Stretch cushion strap assembly and method and device for making
same
Abstract
A laminated stretch cushion strap assembly having a stretchable
cover, a stretchable cushion filler and a stretchable bottom or
bottom fabric. The cover includes a stretchable top fabric, a first
adhesive web layer positioned on one side of the top fabric and a
stretchable base layer positioned on the first adhesive layer on a
side opposite that of the top fabric. The stretchable bottom fabric
forms with the cover an enclosure. The stretchable cushion filler
is adapted to be completely enclosed within the enclosure. The
stretchable cushion filler has a first cushion layer, and adhesive
for securing during lamination the cover to the stretchable cushion
filler, and the cushion filler to the stretchable bottom fabric.
The adhesive is a second adhesive web layer positioned between the
stretchable base layer and the first cushion layer to secure the
cushion filler to the cover, and a third adhesive web layer
positioned on the first cushion layer to secure the bottom fabric
to the cushion filler. The components of the cushion strap assembly
are laminated together completely by heat and adhesive. The present
invention also provides a method and device for making this cushion
strap.
Inventors: |
Tedeschi, Anthony J.;
(Ridgewood, NJ) ; Paschal, P. Benjamin; (Newnan,
GA) ; Petrovich, Joseph M.; (Vernon, NJ) ;
Poindexter, Billy II; (Newnan, GA) ; Falla,
Gloria; (Demarest, NJ) |
Correspondence
Address: |
CHARLES N.J. RUGGIERO, ESQ.
OHLANDT, GREELEY, RUGGIERO & PERLE, L.L.P.
10th FLOOR
ONE LANDMARK SQUARE
STAMFORD
CT
06901-2682
US
|
Assignee: |
Playtex Apparel, Inc.
|
Family ID: |
23024539 |
Appl. No.: |
09/896049 |
Filed: |
June 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09896049 |
Jun 29, 2001 |
|
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09268800 |
Mar 16, 1999 |
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Current U.S.
Class: |
156/213 ;
156/251; 450/86 |
Current CPC
Class: |
Y10T 156/1054 20150115;
Y10T 156/103 20150115; A41F 15/007 20130101 |
Class at
Publication: |
156/213 ; 450/86;
156/251 |
International
Class: |
A41C 003/00 |
Claims
What is claimed is:
1. A laminated stretch cushion strap assembly comprising: cover
means that includes a stretchable top fabric, a first adhesive web
layer positioned on one side of the top fabric and a stretchable
base layer positioned on the first adhesive layer on a side
opposite that of the top fabric; a stretchable bottom fabric that
forms with the cover means an enclosure; a stretchable cushion
filler adapted to be completely enclosed within the enclosure, the
cushion filler comprising a first cushion means; and means for
securing during lamination the cover means to the cushion filler,
and the cushion filler to the bottom fabric, wherein the securing
means includes a second adhesive web layer positioned between the
base layer and the first cushion means to secure the cushion filler
to the cover means, and a third adhesive web layer positioned on
the first cushion means to secure the bottom fabric to the cushion
filler, wherein the components of the cushion strap assembly are
laminated together completely by heat and adhesive.
2. The laminated stretch cushion strap assembly according to claim
1, wherein the assembly is a brassiere shoulder strap.
3. The laminated stretch cushion strap assembly according to claim
1, wherein the first and third adhesive web layers are
stretchable.
4. A laminated stretch cushion strap assembly comprising: a top
cover that includes a stretchable top fabric layer, a first
adhesive web layer positioned on one side of the top fabric layer
and a base fabric layer positioned on the first adhesive layer on a
side opposite that of the top fabric layer; a stretchable bottom
cover that forms with the top cover an enclosure; a stretchable
cushion filler adapted to be completely enclosed within the
enclosure; and means for securing during lamination the top cover
to the cushion filler, and the cushion filler to the bottom cover,
wherein the securing means includes a second adhesive web layer
positioned between the base layer and the cushion filler to secure
the cushion filler to the top cover, wherein the components of the
cushion strap assembly are laminated together completely by heat
and adhesive.
5. The laminated cushion strap assembly according to claim 4,
wherein the securing means includes a third adhesive web layer
positioned on the cushion filler to secure the bottom cover to the
cushion filler.
6. The laminated cushion strap assembly according to claim 4,
wherein the base layer is made of a fabric including nylon and
spandex.
7. The laminated cushion strap assembly according to claim 6,
wherein the base layer includes about 85% nylon and about 15%
spandex.
8. The laminated cushion strap assembly according to claim 6,
wherein the base layer is made of a moldable elastomeric raschel
fabric.
9. The laminated cushion strap assembly according to claim 4,
wherein the cushion filler is made of a fabric including nylon and
spandex.
10. The laminated cushion strap assembly according to claim 9,
wherein the cushion filler is made of a stretch Duplex fabric.
11. The laminated cushion strap assembly according to claim 9,
wherein the cushion filler is made of a fabric including about 89%
filament nylon and about 11% spandex.
12. The laminated cushion strap assembly according to claim 4,
wherein the cushion filler is about 0.140 to about 0.170 inches
thick.
13. The laminated cushion strap assembly according to claim 5,
wherein the first and third adhesive web layers include an
elastomeric copolymeric adhesive web.
14. The laminated cushion strap assembly according to claim 5,
wherein the second adhesive web layer is a substantially
non-stretch web.
15. The laminated cushion strap assembly according to claim 4,
wherein the bottom cover is a bottom fabric layer.
16. The laminated cushion strap assembly according to claim 4,
wherein the base fabric layer and the bottom cover are made of the
same material.
17. The laminated cushion strap assembly according to claim 4,
wherein the top fabric layer is made of an elastomeric raschel
fabric of nylon and spandex.
18. The laminated cushion strap assembly according to claim 4,
wherein the assembly is a brassiere shoulder strap.
19. The cushion strap assembly according to claim 4, wherein the
base fabric layer and the second adhesive layer delaminate when
said assembly is stretched.
20. The cushion strap assembly according to claim 19, wherein the
assembly is a brassiere shoulder strap.
21. A method of making a stretch cushion strap assembly comprising:
laminating a top cover having a stretchable top fabric layer, a
first adhesive web layer positioned on one side of the top fabric
layer and a stretchable base fabric layer positioned on the first
adhesive web layer on a side opposite that of the top fabric layer,
to form a binder layer; positioning a second adhesive web layer on
the binder layer; positioning a stretchable cushion filler having a
first cushion layer on the second adhesive layer; positioning a
third adhesive web layer on the first cushion layer of the cushion
filler, and positioning a bottom fabric layer on the third adhesive
web layer on a side opposite that of the cushion filler; and
laminating together the binder layer, the cushion filler and the
bottom fabric layer to form the cushion strap assembly.
22. The method according to claim 21, wherein laminating includes
molding the binder layer, the cushion filler and the bottom fabric
layer at a first location, said method further comprising cutting
the binder layer and the bottom fabric layer at the first
location.
23. The method according to claim 22, wherein molding includes
heating the tightly held binder layer, cushion filler and bottom
fabric layer.
24. The method according to claim 22, wherein the binder layer, the
cushion filler and the bottom fabric layer are moved into and out
of the first location by a first set of nip rollers and a second
set of nip rollers, said first set of nip rollers located upstream
of the first location, and the second set of nip rollers located
downstream of the first location.
25. The method according to claim 24, wherein said first set of nip
rollers and said second set of nip rollers are electronically
synchronized by a controller to move the binder layer, the cushion
filler and the bottom fabric layer evenly without tension.
26. A device for manufacturing a laminated cushion strap assembly,
the device comprising a mold and cut station for molding and
cutting the strap assembly at a single location.
27. The device according to claim 26, wherein the mold and cut
station includes a device having an upper cutting blade and a lower
mold.
28. The device according to claim 27, wherein the lower mold is
adapted to contact, heat and laminate the cushion strap assembly
before the cutting blade contacts and cuts the cushion strap
assembly.
29. The device according to claim 26, further comprising a first
drive and a second drive located on opposite sides of the mold and
cut station.
30. The device according to claim 29, wherein the first drive is
synchronized with the second drive to move the cushion strap
assembly to and from the mold and cut station under minimal
tension.
Description
[0001] This is a continuation-in-part of application Ser. No.
08/792,059, filed Feb. 3, 1997, which is a continuation of
application Ser. No. 08/553,853, filed on Nov. 6, 1995, which is a
continuation of application Ser. No. 08/162,537, filed Dec. 3,
1993, now U.S. Pat. No. 5,507,681, which issued Apr. 16, 1996.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a strap assembly
and, more particularly, to a stretch cushion strap assembly for use
in a shoulder strap. This stretch cushion strap assembly provides
relief from the normal discomfort associated with shoulder straps,
while maintaining the desired aesthetic appearance even after
repeated machine washings. The strap assembly is uniquely designed
to move with the wearer to support her. In addition, the present
invention provides a method and device for making such a stretch
cushion strap assembly. A primary use of this stretch cushion strap
assembly is in shoulder straps of a brassiere.
[0004] A well known problem associated with brassiere shoulder
straps is the discomfort caused by the strap on the shoulder of the
wearer. Specifically, each brassiere strap will normally cause
either a depression or irritation in the shoulder and may even
interfere with arterial or venous drainage. Numerous attempts have
been made to relieve this discomfort. Some attempts have included
use of shoulder pads of cotton or foam rubber that are interposed
between the strap and the wearer's shoulder or releasably
attachable to the strap.
[0005] Significantly, such pads have proven to be bulky and
unsightly. Also, there are inconveniences attendant with such
attachments since such pads will need to be removed, and
subsequently reattached, each time the brassiere is washed.
[0006] Some brassiere straps have attempted to incorporate a pad
structure in the strap itself. Such brassiere straps may have
achieved a modicum of success in relieving discomfort. However,
such brassieres have limited user life since they fail to maintain
their desired appearance after several machine washings, apparently
due to the effect cleaning detergents have on the construction and
materials of the brassiere strap. Particularly well known is that
pads and straps made of foam have been found to yellow after a few
washings. It is also common that brassieres that have incorporated
a pad therein have a knotted or bumpy appearance after repeated
machine washings. Moreover, none of these straps provided the
comfort of a stretch shoulder strap, that can stretch
longitudinally to move with the wearer.
[0007] Other attempts to relieve discomfort, yet provide a modicum
of pleasing appearance, have included widening the shoulder strap
in order to better distribute the weight in the shoulder area.
Still other attempts have been to incorporate elastic bands with a
padded cover in the strap to provide more flexibility and thus
attempt to better distribute the pressure in the shoulder area.
[0008] These attempts have, heretofore, failed to achieve the
desired results, namely relief of the discomfort in the shoulder
area, with a smooth attractive appearance that is maintained even
after repeated wear and machine washing, combined with flexibility
and give to allow the strap to move with the wearer. Thus, long
wear life and comfort have evaded prior art shoulder straps.
[0009] U.S. Pat. No. 5,507,681 to Smith et al., assigned in common
with the present invention, discloses a Cushion Strap Assembly and
Method of Making Same that addresses most of these problems. The
unique structure and components of the claimed cushion strap
provide a sleek strap that is comfortable and durable.
[0010] The present invention relates to an improved, stretchable
cushion strap that provides additional advantages above and beyond
those disclosed in the Smith et al. patent.
[0011] 2. Description of the Prior Art
[0012] A number of prior art patents illustrate the use of a pad
that is secured to a shoulder strap. For example, U.S. Pat. No.
4,845,785 to F. Allen, titled: Hinged Shoulder Pad, is directed to
a shoulder pad that has a laminated unitary structure arrangement
comprising a plurality of juxtaposed panels overlying one another,
and hinge means integrally connecting adjacent panels to enable
relative flexible pivotal movement therebetween.
[0013] U.S. Pat. No. 4,795,399 to W. W. Davis, titled: Brassiere
Shoulder Strap Bearing Pad, is directed to a bearing pad for
brassiere shoulder straps that is intended to alleviate irritating
indentations to the skin of the wearer The pad comprises a
composite elongated member having two plies of material fastened
together, one of said plies defining an upper ply adapted to engage
one shoulder strap to act as a bearing surface, and the other ply
defining a lower ply for contacting the skin of the wearer. The
upper ply is a stiff, high density, polyethylene synthetic plastic
material, and the lower ply is a low density, soft, non-woven
cushion material comprising polyester fibers. The upper ply has
attaching means that entrap the brassiere strap while permitting
the pad to adjustably slide along the strap for positioning on the
shoulder of the wearer.
[0014] U.S. Pat. No 2,523,720 to W. Riedler, et al., titled:
Shoulder Pad, provides a cover having superposed thereon plies that
are placed one upon another. The plies are preferably formed of a
relatively loose mass of fibers, the surface of which is coated
with a thermosetting plastic and adhesive. See also, U.S. Pat. No.
2,485,720 to G. B. Elliott, et al., titled: Pad For Shoulder
Straps, provides a shoulder pad having an upper fabric layer
adhesively secured to a lower fabric layer, and U.S. Pat. No.
2,511,483 to B. Skirow, et al., titled: Shoulder Pad For Garments
And The Like, that includes a plurality of superimposed layers of
loosely felted fibrous material, and U.S. Pat. No. 2,616,093 to J.
A. Talalay, titled: Apparel Pad, that shows a plurality of layers
of woven fabric separated apart by layers of rubber. Also, U.S.
Pat. No. 3,369,547 to G. H. Sack, et al., titled: Extensible Sheet
Material, that provides an intermediate layer of non-elastic fibers
contained between a top covering layer and a bottom covering layer
of polyurethane sponge that are bonded together by a continuous
heat seal along the edges.
[0015] U.S. Pat. No. 4,945,576 to A. R. Melton, titled: Shoulder
Pad and Brassiere Strap Cushion Apparatus, is directed to a
shoulder pad and strap cushion that includes an outer layer, an
inner layer, cushion means disposed between the outer and inner
layers, and fastening means secured to the inner layer means for
securing the bra strap between the inner and outer layer means of
the pad.
[0016] Other prior art patents provide for the padded material as
an insert or an integral part of the brassiere shoulder strap. For
example, U.S. Pat. No. 2,402,292 to B. Nichols, titled: Shoulder
Pad, discloses a pad or bat of soft material that gives the
shoulder pad substantial thickness. The bat is held in place by the
arrangement of an upper fabric layer and a lower fabric layer that
form a pocket. In addition, the pad is substantially wider at the
mid-portion than at the area at which the straps are connected.
[0017] U.S. Pat. No. 4,100,924 to F. M. Rosenberg, titled: Shoulder
Strap, is directed to a shoulder strap that includes a flexible
elongated main strap portion, a widened flexible intermediate
portion, a first single pocket extending diagonally to the length
of the strap across the intermediate portion, a second single
pocket having a width less than the width of the first pocket and
extending at an angle with respect to the length of the strap
across the intermediate portion, and a pair of stays each disposed
within a pocket. The stays substantially bridge the scapula and
clavicle of the person's shoulder without interfering with arterial
or venous drainage of the shoulder.
[0018] U.S. Pat. No. 3,025,859 to F. M. Rosenberg, titled: Shoulder
Load Carrying Strap, provides a strap that comprises a relatively
wide intermediate supporting portion that is integrally connected
to the respective shoulder strap elements. The strap comprises a
flexible outer fabric layer and a relatively soft yieldable
cushioning material or flexible inner layer that is adapted to
engage the wearer's body.
[0019] Still other prior art patents includes an elastic member, or
form a laminate that include a padded material. For example, U.S.
Pat. No. 4,638,513 to A. J. Woods, titled: Laterally Stabilized Bra
Strap, is directed to a strap that has elastic ribbon means adapted
to stretch in at least the longitudinal direction, padding means
enclosing the elastic ribbon means, smooth-faced material means
enclosing the padding means, and stitching means attaching the
ribbon means, the padding means, and the material means along each
longitudinal edge of the strap.
[0020] U.S. Pat. No. 4,795,400 to B. Greenberg, titled: Brassiere
Strap, provides a brassiere strap that includes a laminate band
consisting of a foam laminate located between an outer laminae, an
inner laminae formed of at least a ply of fabric, and first and
second cold adhesive layers sealing the foam laminae to the outer
and inner laminae. The combined laminate and elastic bands provide
sufficient rigidity to prevent substantial bowing in response to
longitudinal stresses in the brassiere strap, yet sufficient
flexibility to permit the strap to conform to the configuration of
the shoulder of the brassiere.
[0021] U.S. Pat. No. 3,616,148 to I. Edelman, titled: Laminated
Shoulder Strap, is laminated from a nylon tricot fabric tape, a
cotton fabric tape, and a thermoplastic web formed of a material
capable of bonding together tapes. See also U.S. Pat. No. 3,256,131
to A. G. Koch, et al., titled: Embossed Laminate And Method Of
Making Same, which provides a cover material placed over foam that
in turn is placed over backing material, such as nylon fabric, to
form a laminate; and Japanese reference '976 provides a core
material of urethane foam, adhesive and a cover, that are heated
and pressed together.
[0022] U.S. Pat. No. 5,165,113 to A. Hyams, et al., titled: Padded
Straps For Garments and Method of Making Same, is directed to a
padded strap for a garment that includes a core of resilient
material having a pad portion of a first thickness and density, and
a compressed base portion surrounding the pad portion of a second
lesser thickness and second greater density, and tab portions that
provide means for securing the strap to a garment formed from a
part of the compressed portion. The core is, preferably, an
ester-polyurethane foam, although apparently fiberfill can be used.
Also, U.S. Pat. No. 5,240,538 to A. Hyams, et al., titled: Method
For Making Padded Straps For Garments, which is a division of the
application that resulted into the above patent, is directed to a
method of making the padded strap of the above patent.
[0023] Other attempts to distribute pressure and therefore ease
discomfort include U.S. Pat. No. 4,894,868 to P. E. Christopher,
titled: Shoulder Pad Harness, that provides an adjustable narrow
band, first and second shoulder straps and first and second
shoulder pads, and U.S. Pat. No. 4,612,935 to C. R. Greifer,
titled: Comfort Accessories For Brassieres, that is directed to
strap adjusting means.
[0024] U.S. Pat. No. 4,332,633 to K. Yamauchi, et al., titled:
Method For Producing A Shoulder Pad Material, is directed to a
method of producing a shoulder pad blank having a thick walled
portion and a thin walled portion. It specifically provides for
cutting a sheet of shoulder pad stock material sinusoidally into
two intermediate blanks each having a plurality of ridges, as well
as other features. This patent provides for high production yields
by minimizing wasted stock.
[0025] Thus, all of these patents fail to provide the strap
construction of the present stretch cushion strap assembly. They
also appear to fail to use the materials that, in conjunction with
this construction, achieve comfort and long wear life coupled with
a good appearance.
SUMMARY OF THE INVENTION
[0026] Against the foregoing background, it is a primary object of
the present invention to provide a stretch cushion strap assembly
for a shoulder strap that alleviates discomfort and irritation.
[0027] It is another object of the present invention to provide
such a stretch cushion strap assembly and resultant shoulder strap
that have an attractive, non-bulky outer appearance.
[0028] It is still another object of the present invention to
provide such a stretch cushion strap assembly and resultant
shoulder strap that are free of wrinkles and bunching even after
extended use and repeated washings.
[0029] It is yet another object of the present invention to provide
such a stretch cushion strap assembly that is made of materials and
constructed to achieve long wear life.
[0030] It is a further object of the present invention to provide
such a stretch cushion strap assembly that will be used in the
shoulder straps of a brassiere.
[0031] It is a still further object of the present invention to
provide a method and device for making such a stretch cushion strap
assembly.
[0032] To the accomplishments of the foregoing objects and
advantages, the present invention, in brief summary, comprises a
laminated stretch cushion strap assembly having a stretchable
cover, a stretchable cushion filler and a stretchable bottom or
bottom fabric. The cover includes a stretchable top fabric, a first
adhesive web layer positioned on one side of the top fabric and a
stretchable base layer positioned on the first adhesive layer on a
side opposite that of the top fabric. The stretchable bottom fabric
forms with the cover an enclosure. The stretchable cushion filler
is adapted to be completely enclosed within the enclosure. The
stretchable cushion filler has a first stretchable cushion layer,
and adhesive for securing during lamination the cover to the
stretchable cushion filler, and the cushion filler to the
stretchable bottom fabric. The adhesive is a second adhesive web
layer positioned between the stretchable base layer and the first
cushion layer to secure the cushion filler to the cover, and a
third adhesive web layer positioned on the first cushion layer to
secure the bottom fabric to the cushion filler. The components of
the cushion strap assembly are laminated together completely by
heat and adhesive. The present invention also provides a method and
device for making this cushion strap.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The foregoing and still other objects and advantages of the
present invention will be more apparent from the following detailed
explanation of the preferred embodiments of the present invention
in connection with the accompanying drawings wherein:
[0034] FIG. 1 is a perspective view of a brassiere having a pair of
the brassiere straps each incorporating the cushion strap assembly
of the present invention;
[0035] FIG. 2 is a top view of the cushion strap assembly of FIG.
1;
[0036] FIG. 3 is a cross-sectional view of the cushion strap
assembly of FIG. 1;
[0037] FIG. 4 is a perspective, sectional view taken along lines
4-4 of FIG. 1 illustrating the formed bottom portion of the cushion
strap assembly;
[0038] FIG. 5 is a plurality of cushion strap assemblies during the
formation process;
[0039] FIG. 6 is an exploded view of the components used to
manufacture the plurality of cushion strap assemblies; and
[0040] FIG. 7 is a diagram of the device used to make the present
cushion strap assembly.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] Referring to the figures and, in particular, FIG. 1, there
is provided a brassiere generally represented by reference numeral
10. The brassiere 10 includes a pair of shoulder straps 15. Each
shoulder strap 15 has, as shown more clearly in outline form in
FIG. 2, a stretch or stretchable cushion strap assembly 20 of the
present invention.
[0042] Referring to FIG. 3, the cushion strap assembly 20 includes
multiple layers of material and adhesive. In a preferred
embodiment, the multiple layers are approximately seven layers.
These multiple layers can be broken down into three portions,
namely a top cover 60, a bottom cover 62, and a cushion filler 64
that is positioned between the top and bottom covers.
[0043] The top cover 60 includes an outer or top fabric layer 22, a
first adhesive web layer 24 and a base layer 26. The top fabric
layer 22 is a decorative layer that is the top of the brassiere
strap, namely the part of the brassiere strap away from the
shoulder of the brassiere wearer. The top fabric layer 22 is made
of a stretch or into adjacent layers, such as the top fabric layer
22 and the base layer 26, during the laminating process. In the
preferred embodiment, the first adhesive web layer 24 is made of an
elastomeric polyurethane nonwoven web adhesive. Preferably, the
adhesive web layer is made of Spunfab PB7435 stretch adhesive sold
by Spunfab, Ltd. This stretch adhesive has a melting point from
about 228 to about 338.degree. F., a fusing temperature from about
320 to about 340.degree. F., and a tacking temperature from about
304 to about 312.degree. F. This web must not discolor at fusing
temperature, or the finished product will not have an attractive
appearance It is primarily composed of a ternary resin system
polyurethane with a minor amount of additives. This material can
withstand washing and dry cleaning, even when heavier amounts of
adhesive are used. A typical fabric adhesive, such as a polyamide
web adhesive, has a certain amount of crosswise stretch but little
or no stretch in the selvage direction. Thus, the elongation of the
stretchable fabric layers would cause shear stress at the glue
line, causing the layers to pull apart and delaminate over time in
a flexible, stretch strap.
[0044] The base layer 26 is a moldable raschel elastomeric fabric
made of nylon and spandex, preferably a Superlook fabric sold by
Liberty Fabrics under the Style No. 7130. This fabric is made from
about 85% nylon and about 15% spandex, namely a front bar of 40/13
denier S.D. Antron nylon, a middle bar of 40/13 denier S.D. Antron
nylon, and a back bar of 140 denier Lycra spandex. This fabric, as
the base layer 26, has been found to have the desired stability
during the lamination process, while still providing lengthwise
stretch and flexibility to the strap assembly. Basically, it can
withstand shrinkage during heating and has a higher melting point
than various other synthetic fabrics. The preferred base layer 26
was selected for its combination of cost and function. this
material does not require a surface finish because it is enclosed
in the layered package. This allows a less expensive material to be
used. This material does, however, have stretch characteristics
that permit the strap to function well.
[0045] The bottom cover 62 includes a bottom fabric layer 28 The
bottom fabric layer 28 forms the outer or bottom part of the strap
that contacts the skin of the brassiere wearer. The bottom fabric
layer 28 is preferably made of the same material used for the base
layer 26 of the top cover 60, namely a moldable raschel elastomeric
fabric, such as Superlook.
[0046] The cushion filler 64 preferably consists of a single
cushion layer 32. The cushion layer 32 is preferably made of a
nylon/spandex stretch fabric that is more than one layer did not
perform as well as one layer, partly due to the thicker and perhaps
bulky appearance provided by more than one layer. Two or more
layers can be used, preferably adhered together by an elastomeric
copolymeric nonwoven web adhesive such as Spunfab PB7435 stretch
adhesive. However, the use of a single layer is preferred.
[0047] The preferred stretch Duplex fabric is knitted in a five bar
knitting construction, including a first bar of DuPont filament
nylon, a second bar of DuPont Lycra spandex, a third bar of
monofilament nylon, a fourth bar of DuPont Lycra spandex and a
fifth bar of DuPont filament nylon. This results in a fabric of
about 89% nylon and about 11% spandex. This fabric has an
elongation of about 148 to about 180% in a warp direction, and of
about 50 to about 65% in a weft direction. It has also been
discovered that the Duplex cushion is preferably cut at about
90.degree. to the selvage of the fabric to prevent the finished
cushion from rolling up.
[0048] It has been found that fiberfill cannot be used as
effectively as a cushion layer since fiberfill is not as stable.
Also, foam is not desired as a cushion layer since it would
decompose during the heating needed in the process of making the
cushion strap assembly. Further, as stated above, foam has poor
wear life. This is exacerbated in a stretch strap assembly, as the
fiberfill or foam would break down even more quickly when subjected
to repeated stretch and release cycles.
[0049] A second adhesive web layer 30 is positioned between the top
cover 60 or binder layer and the cushion filler 64. Specifically,
it is positioned between the base layer 26 and the first cushion
layer 32 to secure the top cover 60 and cushion filler 64 together
during lamination. The second adhesive layer 30 is preferably made
of Sharnet SH2410-0.06 web. Sharnet is a substantially non-stretch
adhesive web formed of one hundred percent polyamide adhesive. This
is the only layer of the shoulder strap construction that is not
designed to stretch substantially in a lengthwise direction.
However, when the components of the cushion assembly are heated
during lamination, the Sharnet adhesive web layer migrates into the
adjacent layers to form the laminate, and will not impede the
stretching of those layers. This layer is designed primarily to
hold the cushion material in place during processing, and may
delaminate substantially during use without compromising the
performance of the strap assembly.
[0050] A third adhesive web layer 38 is positioned between the
cushion filler 64 and the bottom fabric layer 28 to secure them
together during lamination. Specifically, the third adhesive web
layer 38 is positioned between the cushion layer 32 and the bottom
fabric layer 28. It is preferably made of the same stretch adhesive
as first adhesive web layer 24, most preferably Spunfab PB7435
stretch adhesive.
[0051] Thus, the cushion strap assembly includes the following
layers in sequential order from the top of the brassiere strap: the
top fabric layer 22, the first adhesive web layer 24, the base
layer 26, the second adhesive web layer 30, the cushion layer 32,
the third adhesive web layer 38, and the bottom fabric layer
28.
[0052] The top fabric layer 22, the first adhesive web layer 24 and
the base layer 26 form the top cover 60 of the strap, and the
bottom fabric layer 28 and adhesive layer 38 form the bottom cover
62 of the strap. These top and bottom covers form an enclosure or
enclosed sheath that receives the cushion filler 64. As shown in
FIGS. 3 and 4, the bottom fabric layer 28 forms the depth of the
enclosure. As shown in FIG. 3, the cushion filler 64 does not
contact the ends of the enclosure, but instead there is a space 40
at each end. Thus, the cushion filler 64 would move within the
enclosure if it were not for the second and third adhesive web
layers 30 and 38 (primarily the latter) that secure the cushion
filler 64 into position between the top and bottom covers. The
space 40 accommodates some of the stretching of the cushion filler
64 that occurs during the lamination process, as well as during
wearing and washing of the shoulder strap. Also, the construction
of the cushion filler 64 and the assembly, and the nature of the
materials, permits the stretching and twisting that normally occurs
during both washing and wearing.
[0053] The formed cushion strap assembly provides a sleek strap
having a pleasing aesthetic appearance. It has been found through
preliminary tests that this appearance remains after repeated
washings. This is apparently due to the materials used and the
construction of the cushion strap assembly.
[0054] Referring to FIGS. 5 and 6, this cushion strap lends itself
to the making of several cushion strap assemblies and resultant
straps at the same time. First, the top cover 60 is laminated into
a binder layer. Specifically, the top fabric layer 22, the first
adhesive web layer 24 and the base layer 26 are laminated together
to form a binder layer. The components of the cushion filler 64 can
optionally separately laminated together.
[0055] The cushion filler 64 is then cut to the desired shape,
preferably an elongate oval or biscuit-shaped cushion. Multiple
cushions are then placed in trays, and fed to an alignment station.
The laminated cushions are positioned on the laminated binder layer
and second adhesive web layer 30. Third adhesive layer 38 and
bottom fabric layer 28 are then placed on top of the cushions, to
form the layer structure of the strap. Individual strap assemblies
are then molded and laminated together, and cut out, around the
cushions.
[0056] The cushion filler 64 and the top cover 60 and bottom are
not compressed beyond the normal compression associated with
lamination. Each component's compression, if any, is the same as
that of the other components so that each component is of the same
density, thus providing a good profile and appearance.
[0057] The preferred device and method for forming these shoulder
straps can be understood with reference to the preferred device
depicted in FIG. 7. The laminated binder layer (the top fabric
layer 22, the first adhesive web layer 24 and the base layer 26,
laminated together), slit to the proper width, is fed from roll
102. The bottom fabric layer 28 and the third adhesive layer 38 are
fed as a web from roll 104. Preferably, a paper web is fed from
roll 106. Each layer is automatically unwound with core drive
motors within a loop deadband to minimize tension in the webs in
subsequent processing. These layers are fed first to cushion
loading station 110.
[0058] At cushion loading station 110, cushion feeder and ejector
108 places cushions 111 (cushions 111 preferably include second
adhesive layer 30) between binder layer (22, 24, 26) on one side,
and third adhesive layer 38 and bottom fabric layer 28, on the
other side. The cushions have preferably been loaded into cushion
feeder and ejector 108 by hand. Contemporaneously, binder layer
(22, 24, 26) is heated to process temperature (preferably about
370.degree. F.) by heated platen 113. This causes the cushions 111
to attach to the binder layer. The resulting fabric sandwich is fed
to a mold and cut station 112. The mold and cut station 112 is able
to mold, laminate, and cut out multiple finished shoulder strap
assemblies in a single processing station.
[0059] The mold and cut station 112 includes a two-level device 114
mounted on a hydraulically operated ram 115. Two-level device 114
includes outer, upper cutting forged steel die 116 (or dies) and
inner, lower aluminum spring-loaded mold (or molds) 118. As device
114 is lowered toward the fabric sandwich, mold 118 contacts the
fabric sandwich first. The mold or molds 118 (preferably six or
eight) are brought into contact with the fabric sandwich to a
precisely-controlled height to provide a process mold pressure of
approximately 8 psi by compression of two springs under each mold.
Device 114 is stopped for a short period of time (preferably about
fifteen seconds), while mold 118 shapes and heats the fabric to
laminate the layers and form the strap shape about the cushions.
Mold 118 preferably has a cavity therein that is complementary to
the shape of the cushion, while the other mating surfaces of this
station are flat. A standard cartridge resistance heater is
preferably adjoined to the cavity to heat it to molding temperature
(preferably about 360.degree. F). In addition, mold and cut station
112 preferably includes a heated cutting plate 119 (preferably
about 290.degree. F.).
[0060] After a short delay, die or dies 116 lowers about mold 118
until it contacts and perforates the fabric sandwich. The ram 115
is moved to an adjustable hard limit which allows the strap
assembly to be cut from the web by the dies 116. Preferably, die
116 is dulled at two or more places, such as at two opposing ends,
to leave two points of attachment between the shoulder strap
assembly and the scrap fabric. This allows the sandwich to be drawn
downstream to a subsequent station, where the strap assemblies can
be removed from the scrap fabric with light pressure, preferably by
hand. The kraft paper web from roll 106 is provided to compensate
for uneven cutting height of the dies 118.
[0061] This mold and cut station 112, being a single station,
provides enhanced fabric alignment and processing in less space. In
a machine having separate molding and cutting stations, the heat of
molding can cause the materials to shrink. Different materials
shrink differently when exposed to heat, and even different lots or
batches of the same type of material can respond differently to
high temperatures. Thus, the heat of the molding process can cause
misalignment between the layers, rendering the finished product
commercially unacceptable. The additional step of transferring the
molded fabric to the cutting station increases the opportunity for
misalignment and inaccurate molding, and subsequent cutting, of the
cushion. The present invention addresses these problems, by
consolidating the molding and cutting operations into a single
station.
[0062] The preferred temperature for use in the molding operation
of the mold and cut station 112 is about 340.degree. F. to about
380.degree. F. Most preferred is a temperature of about 360.degree.
F. Heated cutting plate 119 is preferably operated at about
280.degree. F. In addition, at these preferred conditions, the
cushions are ideally molded for a dwell time from about 12 to about
18 seconds, with about 15 seconds being most preferred.
[0063] A fabric sandwich is typically fed through a machine such
as, for example, by a single set of clamps at the downstream end of
the material. These clamps are typically part of an automatic feed
station at which the proper length of material will be pulled
through the machine at each stage. This station draws the strap
material a preset distance at each machine cycle to maintain the
proper component alignment.
[0064] However, when using fabrics that stretch in the machine
direction, like those of the present invention, a single set of
clamps at the downstream end of the fabric pathway is not
effective. These clamps would cause the fabric to stretch, and the
alignment of the layers would fail. Accordingly, the present
invention includes an improved drive system to move the fabric
sandwich of the present invention through the processing
stations.
[0065] This drive system, a geared dual roller arrangement, is used
to eliminate shear in the fabric sandwich by driving top and bottom
rollers at the same speed and distance. The web is accelerated,
driven at constant velocity, and decelerated by a move command
generated by the programmable logic controller 142. This
trapezoidal move profile minimizes "shock" (affecting stretch) to
the web, and is adjustable to compensate for variation in material
especially elongation in a warp direction. The preferred ratio of
output feed length to input feed length is about 1 to about 1.05,
depending on the controlled amount of tension required to process
the web. The trapezoidal move profile is also scaled
accordingly.
[0066] As shown in FIG. 7, drive system 130 includes first drive
132, located upstream of mold and cut station 112, and second drive
134, located downstream of mold and cut station 112. First drive
132 and second drive 134 both include a servo motor 136 belt
driving a geared knurled nip roller 138 seated above the fabric
sandwich. Another driven nip roller 140 is mounted directly below
and synchronized with each driven nip roller 138, and the fabric
sandwich passes between pair of nip rollers. The upper and lower
nip rollers have a slight knurl to drive materials without
slippage, but to avoid `picking` the materials with an overly
aggressive knurled surface.
[0067] Servo motors 136 are synchronized together so that driven
nip rollers 138, 140 on infeed and outfeed are rotated equally and
at the same time. This moves the fabric sandwich evenly, without
stretching or with a small, controlled amount of tension, through
mold and cut station 112. This drive system ensures optimal results
and a minimum number of rejects due to misalignment, stretching or
buckling of layers in the finished strap assembly. The preferred
nip roll force is about 55 pounds, or about 7 psi, over the typical
eight inch width of the fabric sandwich. In addition, it is
preferred that guides 117 are located around the mold and cut
station 112 to keep the cushions 111 centered with respect to die
116.
[0068] Furthermore, drive system 130 can be designed to allow
automatic adjustment of web feed length on each cycle to compensate
for material shrinkage or elongation. This active positioning
reduces material-related defects, and is preferably accomplished by
the addition of photoelectric sensors (not shown) within drive
system 130 to detect reference marks on the web. Programmable logic
controller 142 can use the detected information to adjust drive
feed length while maintaining the preferred output feed
length/input feed length ratios.
[0069] Having thus described the present invention with particular
references to the preferred forms thereof, it will be obvious that
various changes and modifications may be made therein without
departing from the spirit and scope of the present invention as
defined by the appended claims.
* * * * *