Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CA-1027
HEATABLE FLEXIBLE HAIR CURLERS
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to hair curlers for having
hair tresses wound thereon in order to impart a curl
to the hairO In particular, this invention relates to
elongated flexible hair curlers.
Description of the Prior Art
Elongated flexible hair curlers have been known
for quite ~o~e time. Such curlers generally comprise
cylindrical bodie~ ~ade of resilient material such as
foam or sponge rubber and have a wire ~r soft metal
core embedded within the body along the axis ~f the
curler. An elongated flexible curler is much longer
than an inflexible curler in order to enable it to be
bent over on itself to retain a hair tress wound
thereon. This avoids the necessity of a clip to hold
the hair as is required with inflexible curlers.
Elongated flexible curlers also may be bent in a
variety of positions after hair is wou~d thereon and
thus ~ay impart a variety of waves to the hair. The
metal core enables the curler to be bent and to retain
the position it is placed in until it is bent into
another position.
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Examples of one type of elongated flexible curler
are ~hown in U.S. Patent Nos. 1 619 743 and Re. 15 3~3
showing a wire core within a cylindrical pliable rub-
ber coveriny encased in a fibrous ~over. U.S. Patent
Nos. 2 061 817 and 2 542 601 show flexible hair curl-
ers ~aving a central metal core and a compressible
~ponge rubber solid natural or synthetic rubber body
molded around the core. More r~cent prior art is
shown in U.K. Patent Application No. GB 2 111 382
disclosing an elongated curler having a central wire
core ~urrounded by a sleeve and polyethylene foam
jacket and having end caps covering the wire ends.
U.K. patent application GB 2 067 898 shows a curler
having a pipe cleaner core element extending beyond
the curler body in order to enable the ends to be bent
back over the body.
None o~ the aforementioned prior art elongated
flexible curlers is identified as being suitab:le for
being heated and for retaining sufficient heat for a
sufficient time period to facilitate setting a curl in
the hair. Foam rubber curlers are unsuitable ~or heat
retention becau6e they have an open-celled structure
with many air pockets which do not retain heat well.
While ~ome relatively solid material is required to
enhance heat retention solid rubber curlers are
unsuitable because they are relatively hard to the
touch inflexible and continued exposure to heat
would tend to deteriorate the rubber. Natural and
synthetic rubber like that used in the curler referred
to in U.S. Patent No. 2 542 601 generally has duro-
meter reading on the order of 30-100 Shoxe A. This
amount of hardness makes the material not sufficiently
flexible or elastic for sati6factory curler applica-
tions and causes the body material to tend to
~traighten t~le wire. Because of the hardness of the
body material the core wire must ~e relatively large
to overcome the inflPxibility of the rubber. Al~o,
the rubber curler disclosed in 2,542,601 does not
address the issue of fla~mability of the body material
because that curler is not designed t~D be heated. In
a heatable curler nonflammability is important. There
is no sugge~tion in thi~ patent of what material may
be used which has all of the desirable characteris-
tics. Furthermore, there i8 no suggestion in the
aforementioned prior art patents as to how to overcome
the well-known heat-aging propensity of rubber-based
compounds.
U.S. Patent No. 2,074,816 shows an elongated
flexible hair curler having an absoxbent casing filled
with a material uch as calcium oxide which when
moistened generate heat. The curler disclosed in
this patent is incapable of generating heat in use
with dry hairn Additionally, the use of a discrete
chemical composition within the curler requires extra
effort and expense to insure integrity of the calcium
oxide compartment throughout the life of the curler.
It is an object of this invention to provide an
elongated flexible curler capable of being heated and
retaining sufficient heat for a sufficient time to
facilitate setting a curl in hair wound on the curler.
It is a further object of this invention to pro-
vide an elongated flexible curler capable of being
heated dry and of retaining heat for a sufficient time
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in use with either dry or dampened hair to ~acilitate
~etting a curl in the hair.
It i6 yet anothex object of thi~ invention to pro-
viae a heatable elongated fle~ible curler capable o
repeated-and continued exposure to high hair curling
temperatures without significant deterioration,
eapable of being bent substantially 180 and xetaining
such bent position, and having a durometer reading of
approximately 30-70 Shore 00
SVMMARY OF THE I~VENTION
These and other objects of this invention are
achieved by improvement~ in a Elexible hair curler
having a central elongated core capable of being bent
into a plurality of positions and of retaining any
~uch position, the improvement compriæing a vi~co-
elastic polymer body molded about said core and the
ends thereof, said body being heatable by external
means to a predetermined temperature and able to
retain heat for a predetermined ti~e. The product of
the invention may/ because the viscoelastic polymer i8
sufficiently ~upple, be bent into an infinite number
of positions with the relative stiffness of the wire
holding each position as desired.
In ~he preferred embodiment the central core is a
wire having a predetermined ~i~e on the order 16 gauge
the ends of which are bent into loops in order to
aæsist in the retention of the wire within the molded
body and in order to inhibit ~ovement ~f the wire
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within the body to prevent the wire from penetrating
the end6 thereof.
In alternate embodi~ent6, this invention may al~o
compriee a structure having a central elongated core
surrounded by an open-celled foam impregnated with a
predetermined gel having good heat retention qualities
and encased within a flexible tube in order to pre-
fierve integrity of the impregnated foam/gel composi-
tion~
BRIEF DESCRIPTION OF THE DRAWI~GS
Figure 1 shows a plan view of a flexible hair cur-
ler constructed in accordance with the principles of
this invention.
Figure 2 shows a side elevational view of Figure 1.
Figure 3 shows a cross-sec$ional view of Figure 2
taken along the line 3-3.
Figure 4 is a sketch showing several possible con-
figurations into which the flexible hair curlers may
be bent in actual u~e.
Figures 5A and 5B are end and side cross-sections
of an altarnate embodiment of the invention.
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DESCRIPTION OF THE PREFERR~D EMBODIMENT
Referring n~w to Figure 1 there i~ ~hown a plan
view of the preferred embodiment of the invention
æhowing a fle~ible hair curler 10 in an elongated
unbent po ition. By reference to Figure 4 it will be
understood that, in operation, after a hair tre~6 is
wound upon the curler it be bent baek upon it elf or
in a variety of positions in order to xetain the hair
tress thereon without the aid of clips.
Curler 10 includes a central wire core 12 (shown
in phantom in Figures 1 and 2) the ends of which are
bent into loops 14 and 16. Wire 12 i~ embedded within
body 18 and may be either bare or coated with vinyl or
the like. Curler 10 is manufactured in a mold ~not
shown) by having wire 12 retained upon core pins (not
shown) while body 18 i8 injected or cast into the
mold. After body 18 has set, curler 10 is removed
from the mold. The removal of the core pins leave~
apertures 20 and 22 which may remain or may be filled
with a auitable plug material. The core pin~ have a
~emi-circular recess (the complement of which is best
seen in Figur 3) within which wire 12 is held while
the mold sets.
It will be understood that the body 18 must be
~ade of a pliable heat-retaining material able to be
heated by an external means to a predetermined temper-
ature suitable for hair setting and able to retain the
heat for a predetermined time sufficient to set a curl
in the hair wouna upon the curler 10. It has been
found that ~uch a material should be able to r~peat-
edly withstand high temperatures of approximately 100
centigrade ~or relatively long period~ of time and
must be able to withstand repeated exp~sure to Quch
t~mperatures without ~ignificant deterioration. Sueh
material ~hould al ~ be relatively nonflammable and
nontoxic in oxder to be ~uitable ~or con~umer use.
Additionally, ~he ~aterial shvuld have a nonsticky
6urface and be 6ufficiently flexible and pliable in
~rder to enable it to be bent into a vari~_ty of po6i-
tion~ including being bent back up~n it~e:Lf to retain
the haar wound thereupon.~ The mat`erial hould be a
relatively solid mater;~l (i.e. nDn-absorbent)rat ~ ~ a ~oam structure
in order to have the foregoing beneficial characteris-
tic6 and als~ have a high heat capacity and be able to
retain ~he heat for a significant period of time while
conducting it to the hair wound upon the curler. Rub-
ber alone, which was disclosed in the prior art, is
not soft enough or flexible enough to achieve these
functions. Even if it is so~tened with plasticizers
the combination remains unsuitable for consumer use
because the flammability increafies and the plasti-
cizers are extremely corrosive to materials with which
the roller may come in ~ontact (for example, varnish
on wo~d surface~). The material must have all of the
aforementioned characteristic~ and in addition ~hould
feel ~oft to the user to enhance comfort and facili-
tate handling.
It has been found that certain polyurethane based
compounds possess all of the aforementioned desirable
propertie~ and are ~uitable f~r use in flexible hair
curlers. Because of their l~w durometer readings and
vi~coelastic properties, these materials enable u~e of
Gmaller diameter wire than prior art rubber curlers.
For example, the compound S~rboth~ne~ available from
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Sorbothane, Inc., 2144 State Route 59, P.O. Box 178,
Kent, Ohio 44240 i6 a vi6c~ela~tic polymer which has a
very low durometer reading of 30-70 Shore 00.
SQrbothane~ i~ generally de~cribed in U.S. Patent
No. 4~346,205. Other polyurethane comp~und~ may be
~uitable. For example, Mearthane Products Corp., 70
Glen Road, Cran~ton, R.I. 02920 manufaclture~ a Yi6Co-
elastic polymer known aE Mearthane~ which i~ ~imilar
to So~bothane~.
The curler is intended to be used with an external
heat source such as that described in a copending ap-
plication entitled Hairsetter For Flexible Hair
Curlers filed concurrently herewith and assigned to
the assignee hereof, now U.S. Patent No. 4,584,462.
After the curlers are heated in such an external heat
source they may be used to curl hair in the conventional
manner, some examples of which are shown in Figure 4.
It will be under~tood that, while the preferred
embodiment of the invention compri~e~ essentially two
parts -- a core wire and a heatable polyurethane ba~ed
composition -- the advantages of the invention are
achievable by other embodiments. For instance, the central
core wire may have an elongated casing or c~ating surrounding
the wire with end portisns covering the ends of the wire.
The casing or coating may have a heat-retaining, pliable
material embedded substantially throughout it for being heated
and for retaining heat for a period of time sufficient to
enable the curler to be used to curl hair and for
communicating the heat to the casing or coating. Thus,as shown in
Figure~ 5A and 5B the c~ntral core wire could be em-
bedded in a conventional open-~elled ~ylindri~al foam
~hell 30 w~ich could be i~pregnated with a heatable
gel or other comp~siti~n and the entire curler could
then be enca~ed in, for example, a silicone rubber
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tube 32 or other 60ft, pliable liquid imperviou6
casing material~. The gel could alternatively be in-
jection molded with the foam and covered with a plas
ti801 or other coating by 6praying or dipping.
It will be under6tood by tho6e ~killed in the art
that nu~erou~ other improvement6 and modification~ may
be made to the preferred embodi~ent of the invention
diæclo~ed herein without depar~ing from the ~pirit and
~cope here~f. For esample, the ~urface of any of the
embodiment6 di6closed herein may be coated with flock-
ing ~aterial to enhance the soft feel Df the curlers
and tv as~ist in gripping the hair. I'he principle6 of
this invention could also be embodied in hair ~urler~
of various cros~-sectional ~hapes (elliptical,
polygonal, etc.) and various overall ehape~ ~toroidal,
elliptical, etc.). For example, a hair curler could
incorporate a spiral ~roove or ridge along it~ length
or varying diameter along it~ length.
