IMPROVED UNDERWIRE FOR BRASSIERE
Field of the Invention
This invention relates to underwires used in foundation garments such as
brassieres.
Background of the Invention
Underwires are employed to provide shape and supportto brassieres, corsets
and other similar foundation undergarments. They are typically rigid, flat steel
members having a U-shaped configuration, or are formed from a hard, molded or
extruded engineering plastic having some inherent shape and curvature.
Underwires used in the manufacture of brassieres and the like have been
provided with a plastic or polymeric tip at either end. Examples of the construction
and the assembly of underwires having such tips are disclosed in USP 4, 1 33,31 6.
The underwire is maintained in a sleeve or casing that is formed below the
breast cup of the brassiere and that is necessarily made from a soft woven or
knitted fabric. In order to prevent one or both ends of the metal or polymeric
underwire from penetrating the fabric casing and/or pressing uncomfortably
through the garment into the wearer, it has long been the practice to provide the
free ends of the underwire with a tip.
The polymeric tip can be in the form of a molten thermoplastic material into
which the underwire is dipped and then removed and allowed to cool and harden
into a generally spherical shape. Alternatively, the plastic material can be further
shaped while in a pliable state in order to create contours that will easily pass
through the retaining casing when it is assembled to the garment and that will fit
comfortably against the wearer. An improved cushion tip in which a relatively soft
and pliable polymeric material is molded directly on to the free end of the underwire
is described in USP 5,830,040, the disclosure of which is incorporated herein by
reference.
In a second embodiment known to the art, the tip is produced separately
from a polymeric material and then fitted using appropriate retaining means to the
end of the underwire. In a more recent advance in the art, the separate polymeric
tips have been produced using a material that is more pliable and has the feel of
an apparently "softer" terminus to the wearer of the garment.
Despite the advance in the art of providing a more pliable tip having a softer feel, problems are still known to exist. For example, when the wearer assumes
certain positions in which the torso is turned and/or twisted, as in bending over to
pick up something from a position to the wearer's right or left side, the tip of the
underwire which lies beneath the arm tends to exert an extreme pressure against
the end of the fabric casing. Depending upon the age, condition and type of fabric
used in the casing, the tip can puncture the casing. This condition is not readily
reparable and the garment may have to be discarded. In addition, the protruding
tip may contact the wearer's flesh causing extreme discomfort.
Even if the tip of the underwire does not penetrate the casing, the turning
and twisting and/or bending of the torso can still cause the tip of the underwire to press into the flesh beneath the wearer's arm and produce discomfort that spans
the spectrum from merely uncomfortable to painful. Periodic physiological changes
are also experienced by some women in association with their menstrual cycle, as
well as during pregnancy, can results in discomfort at time.
Variations in body types and anatomical differences can also result in
discomfort among some women even when the brassiere is of the "correct" size,
some women also find that a particular style or design of brassiere is not as
comfortable as others because the tip of the underwire produces an undesired
pressure.
Yet another recognized problem is a change that occurs when the garment
is laundered, particularly with respect to shrinkage of the fabric pocket or tube that
retains the underwire in place. Such shrinkage of the fabric of the casing and/or
of the brassiere itself results in a continuous internal force applied by the underwire
tip against the closed end of the casing and premature wear and failure of the casing. Once the underwire has broken through, the garment is deemed to be
unwearable long before its otherwise useful life is reached.
It is therefore an object of the present invention to provide an improved tip
assembly and construction for an underwire which is more responsive to pressures
and forces that are applied during the physical activity of the wearer to thereby
reduce or entirely avoid the application of excessive concentrated force to the
casing containing the underwire and to the wearer.
It is also an object of the invention to provide an underwire having a
resiliently mounted tip that is relatively inexpensive to manufacture and assemble
and which is reliable in its mode of operation and rugged in construction.
Yet another object of the invention is to provide a resiliently mounted tip
assembly and method of construction for an underwire that is adapted for use with
both metal and polymeric underwires and that can be produced from a variety of
materials in various shapes and sizes to accommodate the requirements of the
trade.
Summary of the Invention
The above objects and other advantages are realized in the improved
underwire which comprehends the resilient mounting of a polymeric tip on at least
one end of a garment-supporting underwire. In a first preferred embodiment, the
tip is separately formed, i.e., by molding and/or machining the tip from a polymeric
material having a composition commonly used for such purposes. The tip is
resiliently mounted on a free end of the underwire for sliding movement within a predetermined range. The range of movement of the tip can be determined by the
cooperative engagement of mounting means on the free end of the underwire with
the tip.
In one aspect of this embodiment, a compression spring is mounted between
a retaining shoulder formed on the underwire and the proximal end of the tip.
When a force is applied to the distal end of the tip, the tip slides along the
longitudinal axis of the underwire to compress the spring. When the force is
removed or lessened, the spring urges the tip to return to its original position.
In another aspect of this embodiment, the tip is again mounted on the
underwire in longitudinal sliding relation. A spring which can act in both extension and compression is affixed at one of its ends to a point of attachment on the free
end of the underwire and at its opposite end to a point of attachment on the
slidable tip. As in the earlier-described embodiment, when a longitudinal force
vector is applied to the distal end of the tip, the tip moves along the underwire and
is opposed by the resisting force of the spring in compression. When the
compressive force is removed or lessened, the tip returns to its original position.
In this second aspect of the invention, it is contemplated that the distal end
of the tip is sewn or otherwise secured in position at the end of the casing. Thus,
when the wearer's motion is such that the opposite end and/or intermediate
portion of the underwire is subjected to a force in the opposite direction, i.e., away
from the secured resiliently-mounted tip, the retaining spring expands until such
force is reduced or discontinued, after which the extended spring returns to its
neutral position and brings with it the underwire. This construction has the
advantage of eliminating movement of the tip within the casing, which can lead to
excessive wear of the fabric casing in the vicinity of the tip and to premature
failure of the casing.
The invention also comprehends an underwire in which at least one, but
preferably a plurality of resilient elements are included in, and form an integral part
of the underwire. The one or more resilient members can be displaced from the
point of attachment of the tips, for example, at three spaced apart locations. The
one or more resilient members can take the form of coiled metal expansion and/or
compression springs the ends of which are molded into and retained by the
adjacent sections of the underwire, e.g., a molded plastic composition of a type
known to the prior art. Alternatively, a metal spring can be incorporated by
welding to a section of a metal underwire. In yet another alternative construction,
the one or more resilient members are formed integrally with the underwire, as by
molding of an underwire formed of plastic.
In this latter embodiment, the underwire is produced with at least one
resilient portion that is integrally formed, e.g., by molding, stamping and/or
machining processes known to the art. In a particularly preferred aspect of this
embodiment, the underwire is produced from a polymeric material and is provided
with a plurality of generally V-shaped elements which are joined to form a portion
having a zig-zag or accordion configuration. This configuration responds to
compressive and extensive forces applied longitudinally to the underwire providing
a resistance and reflexive force that is analogous to that of a spring. This resilient
portion of the underwire is preferably positioned adjacent a free end which is
configured to receive a separate tip in fixed relation. Alternatively, the tip can be
integrally molded with the underwire body. When a compressive force is applied
to the distal end of the tip, the integral resilient portion of the underwire is
compressed proportionately. Just as a steel spring has an associated spring
constant value, a similar or comparable value can analogously be calculated for
various configurations of the zig-zag elements forming the integral resilient portion
of the underwire. Other alternative and preferred configurations of flexible
longitudinal elements integrally formed in the underwire are described in more detail
below.
The range of movement of the tip with respect to the underwire is not
critcal. The travel of the tip can be from about 0.12 to about 0.5 inches, or from about 2mm to about 1 3mm. The range can be varied based upon the size and
type or style of the garment; whether one or both ends of the underwire are
provided with resiliently mounted tips, and other factors that will be apparent to
one of ordinary skill in the art.
The tip is preferably formed from a polymeric material that has sufficient
resiliency to deflect when subjected to a lateral force and return to its original form.
The polymer selected should have sufficient elasticity to permit the tip to be
passed over a contoured retaining flange or pin formed on the free end of the
underwire and then return to its original configuration. The polymeric material
chosen for the tip also must have sufficient tensile strength to resist deformation at its points of attachment to the underwire and the end of the spring in the
embodiment described above. Suitable polymers can be selected from the class
of thermoplastic polyoletin elastomers. Products sold in the United States by
DuPont Dow under the trademark ENGAGE®, 8401 and 8402, can be utilized.
The underwire can be fabricated from stainless steel, or steel that has been
galvanized or otherwise coated. Aluminum and aluminum alloys, copper and
copper alloys, steel alloys, and other types of metal can be used without limitation.
As is also known to the art, the underwire can be fabricated from various
polymeric materials and engineering plastics. Suitable polymers, copolymers and
blends used for molding, extruding and machining of underwires can include nylon, polyethylene, butadiene/styrene, acrylonitile/butadiene/styrene, polycarbonates,
polyvinyl chlonde, and others. Desired physical properties can be provided and
enhanced by reinforcing the polymers by addition of glass and carbon fibers to the
liquid resins. Polymeirc or plastic underwire bodies can be of any cross-sectional
configuration and dimension that is known to be useful in the art, and such
features are not critical to the method or apparatus of the invention.
In all of these embodiments, including those last described above, the overall
length of the underwire is reduced in response to a compressive force resulting
from any of a change in the wearer's position, the wearer's anatomy, shrinkage of
the garment, or the application of an excessive strain during mechanical washing.
Thus, the above objects are achieved and other advantages are realized by the
construction and operation of the improved underwire of the invention.
Brief Description of the Drawings
The invention will be further described below with reference to the attached
drawings, wherein like elements are referred to by the same number, and in which:
FIG. 1 is a front left perspective view of a brassiere on a model illustrating
the relative position of the supporting underwires in the garment and to the
wearer's torso;
FIG. 2 is a top left perspective view of one embodiment of an underwire
suitable for use in supporting the cup illustrated on the left side of Fig. 1 ;
FIG. 3 is a side elevation view of the resiliently mounted tip and a portion of
the underwire taken along section line 3-3 in Fig. 2;
FIG. 4 is a front elevation view, partly in section, taken along section line 4-
4;
FIG. 5 is a view similar to Fig. 4 showing the effect of a compressive force
applied to the free end of the tip;
FIG. 6 is a view similar to Fig. 5 illustrating another embodiment of the
invention employing a compressible foam element, the effect of a compressive
force being shown in phantom;
FIG. 7 is a side elevation view of a tip and a portion of the free end of the
underwire illustrating another embodiment incorporating an integral resilient
member on the underwire;
FIG. 8 is a front elevation view of the tip and underwire of Fig. 7, taken
along line 8-8, the effect of a compressive force being shown in phantom;
FIG. 9 is a front elevation view, partly in section, schematically illustrating
a portion of the free end of underwire with a spring-mounted tip;
FIG. 1 0 is a view similar to Fig. 9, showing the effect of an extensive force
applied to the tip;
FIG. 1 1 is a view similar to Fig. 9, showing the effect of a compressive force
applied to the tip;
FIG. 1 2 is a front elevation view of a further embodiment of the invention
showing a tip integrally formed in the end of the underwire and incorporating an
intermediate flexible section;
FIG. 1 3 is a view similar to Fig. 1 2 showing the effect ont he resilient
section of a compressive force applied to the tip;
FIG. 14 is a front elevation view of another embodiment of the invention
showing a separate tip spring-mounted on the free end of the underwire, the effect
of a compressive force applied to the tip being shown in phantom; and
FIG. 1 5 is a side elevation view in section of the embodiment of Fig. 14,
taken along line 1 5-1 5.
FIG. 1 6 is a front elevation view of another preferred embodiment of the
invention that includes a resilient member in the underwire at a location displaced
from the tips;
FIG. 1 7 is a front elevation view similar to Fig. 1 6 of a further preferred
embodiment in which the underwire includes a plurality of resilient members.
Description of Preferred Embodiments
For the purposes of providing a clear understanding of the principles of the
invention, reference will be made to the embodiments illustrated in the drawings and a detailed description of each will be provided. It will, nevertheless, be
understood that no limitation of the scope of the invention is thereby intended,
such alterations and further modifications in the illustrated devices, and such
further applications of the principles of the invention as illustrated therein being
contemplated as would normally occur to one skilled in the art to which the
invention relates.
With reference to Fig. 1 , there is illustrated a brassiere constructed in
accordance with the prior art showing the relative position of a pair of separate
underwires 2 with tips 4 rigid affixed to each of the free ends of the underwire.
The underwires are positioned inside of fabric casings that are sewn into the garment.
Referring now to Fig. 2, there is shown an underwire assembly 10 in
accordance with the present invention formed from a flat steel strip 1 2, preferably
a stainless steel or a galvanized or otherwise coated steel that will be resistant to
rust and corrosion. As shown, the underwire 10 is arcuate in form, its contour
corresponding to that of the casing affixed to the periphery of the brassiere cup
into which the underwire will be inserted to provide shape.
As best shown in Figs. 3-5, at least one free end 14 of the underwire 1 2 is
configured to receive and retain a tip 40 that is mounted in sliding relation in
accordance with the method and apparatus of the invention. In the embodiment
illustrated, a pair of tapered retaining flanges 20 project transversely in the
longitudinal plane of the underwire 12. Each of the retaining flanges extend
outwardly from the distal portion of the free end of the underwire to terminate at
a retaining edge which is generally normal to the longitudinal axis of the underwire.
Spring retaining shoulder 24 is formed adjacent narrowed portion 22 extending
from the wider end of underwire 1 2. In this embodiment, the narrowed portion 22
is adapted to receive a coil compression spring 30, as best shown in Fig. 4. The
longitudinal distance between flange 20 and spring retaining shoulder 24, less the
height of the compressed spring 30, determines the longitudinal distance which
the tip can move in response to a force that is applied to its distal end 42.
With further reference to Figs. 2 through 5, the tip 40 is formed with gently
rounded distal end 42 and contoured with outwardly tapering top and bottom
surfaces 44 terminating in proximal end 46. Since the tip is to be inserted for
movement through, and in, a soft fabric casing, all corners and edges are
preferably rounded and smoothed to prevent snagging or tearing and fraying of the
adjacent fabric. The maximum width or transverse dimension of the tip 40 can be
approximately that of the flat metal underwire 1 2. The thickness of the tip is
sufficient to receive the free end of the underwire 1 2 in close-fitting sliding
relation, while providing sufficient surrounding material to avoid cracking or
deformation of the tip during assembly to the underwire and to insure that the tip
maintains its form and integrity during wear and cleaning.
With reference to Fig. 6, a further embodiment of the invention is shown in
which the resilient member takes the form of a compressible polymeric foam that
is positioned in the distal end of channel 48 of tip 40. When a force F is applied
to the distal end 42 of the tip, the distal surface of free end 1 4 contacts and
compresses the foam thereby reducing the overall length of the underwire
assembly 1 0.
As shown in the further preferred embodiment of Figs. 7 and 8, the
underwire body 1 2 is provided with integrally formed resilient members in the
nature of a series of contiguous V-shaped elements 70 that extend for a
predetermined longitudinal length and, in the embodiment shown, extend
transversely across the full width of the underwire body. This zig-zag or accordion¬
like section can be formed at the time of manufacture of the underwire, as by
molding. Alternatively, this type of resilient member can be formed by machining
a previously produced underwire body 1 2. As will be apparent to one of ordinary
skill in the art, the relative flexibility and a corresponding desired equivalent spring
constant value can be achieved by a variety of means. Such variables include the
composition of the polymer employed; the thickness and configuration of the zigzag elements, as well as the precise configuration of the regions at which they are
joined; the thickness of the material; the length and number of the section(s)
comprising the resilient member; and the like.
As will be understood from the above description of the various
embodiments, the resilient member 25, whether it be in the form of a spring
formed of coiled wire or formed from the same material and integral with the
underwire body 1 2, can be of a compression type or of a compression-expansion
type. In the case of a compression spring, the overall length of the underwire
assembly 1 0 can be reduced in response to a force applied to one or both tips. In
the case in which a compression-expansion spring is employed, the length can be
both decreased and increased in response to the corresponding forces on the
garment casing and/or tips of the underwire.
Referring now to Figs. 9 through 1 1 , there is illustrated a further preferred
embodiment where the tip 40 is joined to the free end 1 4 by a spring 90 that acts both in compression and expansion. Fig. 9 shows the assembly in a neutral
position with the free ends 92 of spring 90 secured in aperture 1 6 in free end 14
and in aperture 41 of tip 40. As illustrated in each of the cross-sectional views,
the spring is positioned in channel 48 that extends axially through skirt 43
depending from the distal end 42 of tip 40. In this embodiment, tip 40 is provided
with a retaining aperture 52 to permit it to be secured, as by stitching, to the
casing and/or underlying body of the garment to prevent it from moving once it has
been properly positioned in the casing. Alternatively, tip 40 can be produced from
a polymeric material that is sufficiently soft to permit the penetration of a sewing
machine needle without providing aperture 52 for that purpose.
As shown in Fig. 1 0 when a force is applied tending to separate the tip from
the underwire body, spring 90 expands, thereby providing an effective elongation of the underwire assembly 10. When the force is diminished or eliminated, the
spring 90 returns tip 40 to its original neutral position, i.e., as in Fig. 9. As shown
in Fig. 1 1 , when a compressive force is applied, the spring 90 is compressed, the
effective length of the underwire assembly 10 is reduced and the skirt 40 slides
down the underwire. Upon dimunition of the compressive force, the spring
expands to the neutral position and returns the tip to its original position.
A further embodiment will be described with reference to Figs. 1 2 and 1 3,
in which the resilient member is comprised of a plurality of elongated elements 100
formed in the underwire body 1 2. Although not shown for reasons of clarity and
simplicity, it will be understood that a separate tip can be fitted to the free end 14.
As illustrated in Fig. 1 3, when a compressive force is applied to the distal end of
the underwire, the elements 50 are configured to flex and assume a curvilinear
configuration, thereby reducing the effective length of the section in which the
resilient member is formed. When the compressive force is reduced or eliminated,
the longitudinal elements 100 will straighten to assume their original configuration
and effective length.
For purposes of illustration and convenience, a pair of flexible elements 100
is shown in Figs. 12 and 1 3; however, as will be apparent to one of ordinary skill
in the mechanical arts a greater or fewer number of such elements can be
incorporated in order to achieve a desired effective reduction in length in response
to anticipated forces. The considerations of design to be applied are that the
polymeric material can withstand a sufficient number of flexings and has sufficient recovery properties to return the tip to its desired positional location within the
casing. The longitudinal elements 100 can be curved, weakened in one area, or
otherwise configured to be predisposed to assume a particular oriental when a
compressive force is applied.
A further preferred embodiment of the invention is shown in Figs. 14 and
1 5. As in the embodiment of Figs. 3-5, a compression spring 30 is mounted on
a narrowed portion of the free end 1 4 of underwire body 1 2. Tip 40 is secured for
longitudinally sliding movement by a retaining pin 56 which in a preferred
embodiment is integrally formed in the free end 14. Tip 40 is provided with a
retaining slot 58 that corresponds in length to the range of movement of the distal
end of the tip. As will be understood from the illustration, the length of slot 58
can correspond to the difference in length of the compression spring 30 in its
neutral position and its fully compressed position.
With reference to Figs. 1 6 and 1 7, two further embodiments are
schematically illustrated in which one or more resilient members are incorporated
into the underwire body 1 2 at positions longitudinally displaced from the tips 40.
The resilient members, referred to generally as 25, can be of the type and
configuration described in connection with Figs. 7 and 8, above, or can take the
form of steel coil springs. In the case in which steel springs are employed, the free
ends of each spring are secured to the adjacent portion of the underwire body 1 2.
In the case of a polymeric underwire body 1 2, the springs can be incorporated advantageously in the initial fabrication of the assembly, as by molding; the springs
can be welded to metal underwire body sections to form a unitary assembly. In
either case, the resilient member or members form an integral construction with the
adjacent underwire sections, and possess sufficient strength and rigidity to be
passed through the fabric casing during assembly of the garment and to withstand
wear and repeated laundering.
It will also be understood that in the embodiment illustrated by Figs. 14 and
1 5 that the assembly does not require either end of the spring to be secured to
either the underwire body 1 2 or the tip 40, thus simplifying and making this
construction relatively less expensive. In order to complete the assembly, the tip
40 is fabricated from a polymeric material that is capable of being deformed
sufficiently to allow the retaining pin 56 to pass through the interior axial channel
48 by expanding the cross-sectional configuration of the channel, and thereafter
returning to its original cross-section when the pin 56 is received in exterior slide
slot 58. This means of assembly will be known to those of ordinary skill in the art
as having been used with fixed tips on the free end of the underwire.