Hair Straightening Apparatus

Abstract

An improved hair iron for straightening or styling hair is presented. The hair iron comprises two arms pivotally connected at one end and includes a biasing spring near the pivot and connected to arms to bias the arms in a normally open position. Included on one arm is a positive temperature coefficient (“PTC”) heater with a tourmaline coating on the heating surface. Inclusion of a single heating surface on only one arm reduces the risk of heat damage to the hair-to-be-styled and likewise reduces the iron's energy consumption. Included on the other, non-heated, arm is a compressible element for gripping the hair-to-be-styled. The compressible element minimizes the risk of damage to the hair from potential over-compression of the arms of the iron by the stylist. Consequently, the fullness or volume of the styled hair is increased.

Description

FIELD OF THE INVENTION

The present invention relates generally to the field of hair straightening devices or hair irons, and in particular, to an improved hair straightening device that causes less damage to hair and is more energy efficient. The improved hair straightening device is suitable for use in beauty salons, barber shops, and homes.

BACKGROUND OF THE INVENTION

Many types of hair straightening devices (also referred to as hair irons) are presently available for commercial sale. Prior art hair irons typically comprise two arms connected by a pivot and a biasing spring at one end. The spring biases the arms into an open rest position at their free ends. The free end of each arm is typically equipped with a heating element having a metal and/or ceramic surface for applying heat to the hair-to-be-styled or straightened. By pressing on the arms of a hair iron, a stylist may move the two arms towards one another through a variable angle to bring the heating surfaces into contact with each other, or with the hair-to-be-styled. The hair-to-be-styled is placed between the heating elements and is either gripped and drawn between the arms, or the arms are moved down the length of the hair shafts. The hair is straightened as a result of the heat and pressure that is applied to the hair. In instances where the hair is wet when the hair iron is applied, the heating surfaces are typically sufficiently hot to flash the water present in the hair to steam, which enhances the straightening process.

One drawback to the use of conventional hair irons is the risk of damaging the hair upon exposure to the heat and pressure applied to the hair during styling. For example, the heating elements of common hair irons are typically composed of metal and/or ceramic and their heating surfaces and may be heated to a relatively high temperature, i.e. up to about 500 degrees Fahrenheit. Hair in direct contact with the two heated surfaces common to prior art hair irons can be rapidly heated to excessive temperatures which may in some instances lead to scorching of the hair, or other heat related damage.

In addition, the metal and/or ceramic materials from which the heating surfaces are typically made are relatively hard and unyielding. When the hair to by styled is gripped between two hard heating surfaces, it is all too easy for a stylist to apply excess pressure and in so doing crush the hair or inflict other physical damage to the hair such as kinks, undesired bends, split ends, and the like. Hair can also be flattened by the excess heat and pressure generated by prior art hair irons. All of the aforementioned types of damage sharply reduce the pleasing appearance of the hair and consequently defeats the purpose of having hair styled.

There is, thus, a need in the hair styling art for an improved hair iron that is . less likely to inflict damage upon the hair being styled. Such an improved iron would reduce damage to the hair by subjecting the hair to less heat and thereby reduce the risk of scorching. Such an improved hair iron should also reduce the risk of hair damage caused by heat and/or pressure on the hair by providing one of the free ends of the iron with a compressible surface so as to reduce the risk of crushing, kinking, flattening, or bending the hair, and of causing split ends. It would also be desirable for such an improved hair iron to reduce energy consumption over that of prior art hair irons.

SUMMARY OF THE INVENTION

The present invention hair iron solves the problems associated with prior art hair irons by equipping only one of the two arms of the hair iron with a heating element, unlike prior art hair irons which use heating elements on both arms. The non-heated arm of the new hair iron is equipped with a compressible element. By equipping only one arm with a heating element, the present invention hair iron reduces the heat load applied to the hair to be styled, and therein significantly reduces the risk of scorching, flattening, or other heat related damage. By reducing heat related damage, the present invention hair iron allows the hair to retain volume. Energy consumption is also significantly reduced.

By equipping one arm of the iron with a compressible element rather than a second heating element, the new iron substantially reduces the likelihood of damage to the hair-to-be-styled which often occurs due to stylists exerting too much force on the arms of the iron and thereby apply excessive pressure and over-compress the hair. By reducing the likelihood of hair damage due to over-compression, the present invention allows the hair to retain fullness, i.e. volume. Achieving a reduction in the amount of bent, crushed, flattened, or kinked hair, as well as split ends, provides a substantial improvement over prior art irons. The compressible element on the non-heated arm of the iron may also include a textured surface that aids in maintaining the fullness of the hair-to-be-styled. Additional features such as a tourmaline-composition coating on the heating surface and a positive temperature coefficient (“PTC”) heater with variable heat output and automatic shut-off are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hair iron in accordance with the principles of the present invention, shown in the normally open position.

FIG. 2 is a side view of the hair iron shown in FIG. 1.

FIG. 3 is an enlarged perspective view, partially cutaway, of the an embodiment compressible element of the hair iron of FIG. 1.

FIG. 4 is a perspective view of the hair iron of FIG. 1, shown in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 through 3, the present invention comprises a hair iron 10 having an upper (or first) arm 12 and a lower (or second) arm 14. The upper and lower arms 12 and 14 are pivotally connected at one end by a pivot 16. The ends of the upper and lower arms 12 and 14 opposite the pivotally connected ends are free ends. The upper and lower arms 12 and 14 are able to open and close via rotation of the constrained ends about the pivot 16. A biasing spring 18 (not shown) is located adjacent to the pivot 16 and connected to the arms 12 and 14 such that the spring 18 biases the arms into a normally open position at an acute angle when at rest. By squeezing the arms, a stylist may cause the arms 12 and 14 to move to a closed position in which the arms are substantially parallel to one another. References herein to “upper” and “lower” arms are used for convenience only and are not intended to limit the orientation of the device set forth herein.

The upper and lower arms 12 and 14 comprise upper and lower gripping portions 20 and 22, respectively, which are disposed near the pivot 16. The gripping portions 20 and 22 allow the stylist to grip and manipulate the hair iron 10. The gripping portions 20 and 22 may optionally be equipped with a textured or contoured surface (not shown) to assist in preventing slippage of the hair iron in a stylist's hand. The upper and lower arms 12 and 14 further include upper and lower hair treatment portions 24 and 26, respectively, which are disposed adjacent the free ends of the arms. The upper hair treatment portion 24 includes a heating element 28 which includes a substantially flat, hair-contacting heating surface 30 (best shown in FIG. 2). An electrical cord 32 is disposed within the upper arm 12 and is in electrical connection with the heating element 28. The lower treatment portion 26 of the lower arm 14 includes a compressible element 34, which may be a pad or similar compressible material, and which has a hair-contacting portion 33.

The compressible element 34 protects the hair-to-be-styled 42 (shown in FIG. 4) from physical damage. In comparison to the hard, rigid surface of a ceramic or metallic heating element, the compressible element 34 yields and thereby diminishes the compressive force applied to the hair by the stylist when squeezing the arms 12 and 14 of the hair iron 10 against the hair 42. By diminishing or relieving the compressive force applied to the hair, the compressible element 34 tends to increase the fullness, i.e. volume, of the hair-to-be-styled. The compressible element 34 also allows a degree of lateral movement of the hair along the surface of the element which also aids in reducing physical damage to the hair 42.

The compressible element 34 may optionally include a pattern 36 of alternating peaks 38 and valleys 40, or more generally, alternating raised and lowered surfaces. Such a pattern tends to further reduce the risk of damage to the hair 42 by over-compression of the arms 12 and 14 of the iron 10 and provides a further degree of lateral movement between the hair and the element, i.e. the hair can slide between the alternating surfaces of the element. A depth of about 0.05 to about 0.100 inches between the peaks and valleys of the alternating surfaces has been found to be suitable. Other depths may also be suitable. Suitable patterns for the alternating peaks and valley include, without limitation, repeating squares, rectangles, and triangles, among others. In other embodiments, the compressible element 34 may have a substantially flat hair-contacting surface 33 rather than one of alternating peaks and valleys.

The upper and lower arms 12 and 14 may be made of any suitable material. Various ceramic, plastic, and metallic materials are suitable and are known in the art. In one embodiment the arms 12 and 14 are made from heat resistant plastic.

The heating surface 30 of the heating element 28 is generally rectangular in shape. In one embodiment of the hair iron 10, the heating element comprises multiple elements consisting of one inch square surfaces or plates. The heating elements or plates may optionally be “floating plates,” i.e. plates that allow for some lateral and downward movement into the upper arm 12, which may further reduce the incidence of hair damage caused by heat and pressure applied to the hair. The heating element automatically shuts off after a predetermined period of nonuse. The heating element temperature can be made adjustable from a minimum temperature of zero degrees to a maximum temperature of about 450 degrees Fahrenheit. Optionally, the present invention hair iron 10 may include a universal voltage feature, i.e. the iron 10 may be equipped with circuitry to allow the iron to operate from either domestic 110 volt AC current or 220 volt AC current as is common outside of the United States.

Multiple types of heating elements are suitable for use in the present invention and are known in the art. However, positive temperature coefficient (“PTC”) heaters are preferred. PTC heaters are composed of ceramic materials and are noteworthy because they exhibit low electrical resistance at ambient temperature and then gradually increase in resistance as they are heated by electric current passing through the unit. PTC heaters also exhibit a large increase in electrical resistance upon reaching their maximum temperature which in turn causes current flow to be greatly reduced. Consequently, PTC heaters can maintain equilibrium at their maximum operating temperature while drawing a comparatively small steady state current. A PTC heater's maximum operating temperature is a function of material composition. PTC heaters are advantageous because they provide a large amount of heat while being self-regulating, and hence, are well suited for use in the present invention. One non-limiting example of the internal construction of a suitable PTC heater is disclosed in U.S. Pat. No. 3,996,447.

The heating surface 30 of the heating element 28 may optionally be equipped with a surface coating 48 (best shown in FIG. 2) comprising, at least in part, the mineral tourmaline. Methods of deposition of tourmaline coatings upon ceramic, plastic, and metallic substrates are known in the art. Tourmaline, also known as complex aluminum borosilicate, has been adapted to hair styling tools because when heated, the material exhibits pyroelectricity. Pyroelectricity is the ability of certain materials to generate a temporary electrical potential when they are heated or cooled. When heated, tourmaline is believed to emit negatively charged ions. It is believed within the hair styling industry that these negatively charged ions help smooth hair by sealing the cuticles, and by assisting in the retention of moisture. The effects of heated tourmaline are believed to make hair appear smoother, shinier and healthier. Tourmaline coatings also typically result in a smoother surface than ceramic. Consequently, less friction is produced as hair is pulled through the tool, resulting in less damage to the hair.

The compressible element 34 of the present invention may be made from any material which can withstand temperatures of up to about 450 degrees Fahrenheit. Several cloth materials are suitable and are known in the art. One suitable material is polytetrafluoroethylene (“PTFE”). PTFE is commercially available from EI Dupont de Nemours and Company (“Dupont”) under the Teflon brand. The compressible element 34 may also be constructed from aramid fibers which are commercially available from Dupont under the Kevlar and Nomex brands. Suitable fabrics comprising a blend of one or more of the above materials and other materials are also known in the art.

Operation of the Invention

Referring now to FIGS. 1-4, in operation, a stylist will first turn on the heater 28 of the present invention hair iron 10. (The hair iron 10 will typically be equipped with an on/off switch as is known in the art.) When the exposed exterior hair-contacting surface 30 of the heating element 28 reaches the desired temperature, the stylist then places the hair-to-be-styled 42 between the heating surface 30 of the upper hair treatment portion 24 of the upper arm 12 and the hair-contacting portion 33 of compressible element 34 of the lower treatment portion 26 of the lower arm 14. The stylist then closes the hair iron 10 by pressing on the upper and lower gripping portions 20 and 22 of the upper and lower arms 12 and 14 until the arms are in the substantially parallel closed position. The stylist begins at the root ends 44 of the hair-to-be-styled 42 and proceeds to draw the hair through the iron 10 to the hair tips 46. Alternatively, rather than draw the hair-to-be-styled 42 through the hair iron 10, the stylist my move the iron 10 along the hair-to-be-styled 42 from the initial position at the root ends 44 to an end position at the hair tips 46. The process of drawing the hair-to-be-styled 42 through the iron 10 may be repeated several times until the hair 42 has achieved the desired degree of straightness or styling.

Advantages of the Present Invention

The present invention hair iron 10 provides distinct advantages over the prior art. By equipping the hair iron 10 with only a single heating element 28 on the upper arm 12, the present invention hair iron dramatically reduces the heat load applied to the hair-to-be-styled 42 and therein significantly reduces the risk of scorching or other heat-related damage to the hair. Likewise, energy consumption is also significantly reduced over prior art hair irons which feature heating elements on each arm of the hair iron. By equipping the non-heated or lower arm 14 of the hair iron 10 with a compressible element 34 rather than a hard or rigid surface, the present hair iron 10 substantially reduces the likelihood of damage to the hair-to-be-styled 42 which frequently occurs when stylists over compress the hair by exerting too much force on the arms 12 and 14 of the iron 10. The compressible element 34 feature leads to significant reduction in the amount of bent, crushed, flattened, or kinked hair, as well as split ends. As mentioned above, because both the compressive force and heat applied to the hair-to-be-styled is decreased, the present invention hair iron consequently increases the fullness or volume of the hair.

The foregoing detailed description and appended drawings are intended as a description of the presently preferred embodiments of the invention and are not intended to represent the only forms in which the present invention may be constructed and/or utilized. Those skilled in the art will understand that modifications and alternative embodiments of the present invention which do not depart from the spirit and scope of the foregoing specification and drawings, and of the claims appended below are possible and practical. It is intended that the claims cover all such modifications and alternative embodiments.

Claims

1. A hair iron comprising:

first and second arms pivotally connected at one end, wherein the arms are able to move from an open position to a closed position for the purpose of gripping hair;

the first arm having a heating element integral with the first arm and disposed along its free end; and

the second arm having a non-heated compressible element integral with the second arm and disposed along its free end.

2. The hair iron of claim 1, further comprising a biasing spring adjacent the pivot and connected to the first and second arms such that the arms are biased to a normally open rest position at an acute angle.

3. The hair iron of claim 1, wherein when the first and second arms are closed they are substantially parallel.

4. The hair iron of claim 1, wherein when heating element comprises a PTC-type heater.

5. The hair iron of claim 1, wherein the heating element comprises a hair-contacting heating surface that is coated with a material containing tourmaline.

6. The hair iron of claim 1, wherein the non-heated compressible element has a hair-contacting portion that is substantially flat.

7. The hair iron of claim 1, wherein the non-heated compressible element comprises a hair-contacting portion having a pattern of peaks and valleys.

8. The hair iron of claim 7, wherein the depth from peak-to-valley of the pattern of the alternating surfaces is approximately 0.05 inch to 0.100 inch.

9. The hair iron of claim 8, wherein the compressible element is made from a material selected from the group consisting of polytetrafluoroethylene, aramid fibers, polytetrafluoroethylene blended with other materials, and aramid fibers blended with other materials.

10. The hair iron of claim 1, wherein the heating element comprises one or more floating plate-type heating elements.

11. The hair iron of claim 5, wherein the non-heated compressible element comprises a hair-contacting portion having a pattern of peaks and valleys.

12. A hair iron comprising:

first and second arms pivotally connected at one end, wherein the arms are able to move from an open position to a closed position for the purpose of gripping hair;

the first arm comprising a PTC-type heating element integral with the arm and disposed along its free end;

the PTC-type heating element comprising a hair-contacting heating surface coated with a composition containing tourmaline;

the second arm comprising a non-heated compressible element integral with the arm and disposed along its free end; and

the non-heated compressible element comprising a hair-contacting portion having a pattern of peaks and valleys.

13. The hair iron of claim 12, further comprising a biasing spring adjacent the pivot and connected to the first and second arms such that the arms are biased to a normally open rest position at an acute angle.

14. The hair iron of claim 12, wherein when the first and second arms are closed they are substantially parallel.

15. The hair iron of claim 12, wherein the depth from peak-to-valley of the pattern of peaks and valleys is approximately 0.05 inch to 0.100 inch.

16. The hair iron of claim 12, wherein the compressible element is made from a material selected from the group consisting of polytetrafluoroethylene, aramid fibers, polytetrafluoroethylene blended with other materials, and aramid fibers blended with other materials.

17. The hair iron of claim 12, wherein the heating element comprises one or more floating plate-type heating elements.

18. A hair iron comprising:

first and second arms pivotally connected at one end, wherein the arms are able to move from an open position to a closed position for the purpose of gripping hair;

a biasing spring adjacent the pivot and connected to the first and second arms such that the arms are biased to a normally open rest position at an acute angle;

wherein, when the first and second arms are closed they are substantially parallel;

the first arm comprising a PTC-type heating element integral with the arm and disposed along its free end;

the PTC-type heating element comprising a hair-contacting heating surface coated with a composition containing tourmaline;

the second arm comprising a non-heated compressible element integral with the arm and disposed along its free end;

the non-heated compressible element including a hair-contacting portion having a pattern of peaks and valleys; and

the pattern of peaks and valleys having a depth from peak-to-valley of approximately 0.05 inch to 0.10 inch.

19. The hair iron of claim 18, wherein the heating element is adjustable from zero degrees to approximately 450 degrees Fahrenheit.

20. The hair iron of claim 18, wherein the heating element automatically shuts-off after non-use for a predetermined period of time.