EP1613187A2

EP1613187A2 - Curling iron with conical barrel

Info

Publication number: EP1613187A2
Application number: EP04750132A
Authority: EP
Inventors: Martin A. Cohen; Vito James Carlucci
Original assignee: Conair Corp
Current assignee: Conair Corp
Priority date: 2003-04-15
Filing date: 2004-04-15
Publication date: 2006-01-11
Also published as: WO2004091335A3; WO2004091335A2

Abstract

A curling iron for heated styling of hair. The curling iron includes a conical barrel, a heater located in in the conical barrel for providing thermal energy to heat the conical barrel, a precise temperature control for accurately controlling a heating temperature of the conical barrel, and at least one heat sink for forcibly holding the heater in the conical barrel and for conducting thermal energy from the heater to the conical barrel.

Description

CURLING IRON WITH CONICAL BARREL

BACKGROUND OF THE INVENTION

1. Field of the Invention

[001] The present invention relates to a curling iron. More particularly, the present invention relates to a curling iron that has a conical shaped barrel to facilitate styling hair manipulated and shaped by the curling iron.

2. Description of Related Art

[002] Heated hair may be smoothed, manipulated, and styled more easily that non-heated hair. There are numerous hair styling tools and appliances for heated styling of hair. Such hair styling tools and appliances include curling irons of various configurations having a variety of features. Curling irons are intended to impart a curl or pattern to hair being styled by the curling iron. In general, curling irons impart a curl or pattern to hair being styled by sufficiently heating a barrel or mandrel of the curling iron and restraining the hair in physical contact with the barrel to thermally heat the hair. A section of hair is typically wound around the heated barrel of the curling iron and held in contact with the heated barrel for a period of time. Heat from the heated barrel reforms plastic bonds in the hair. When the heat styled hair is removed from the heated barrel the hair retains the shape of the curling iron's barrel.

[003] Curling iron barrels are generally cylindrical in shape and manufactured as metal or metal coated rods or cylinders. Various heaters or heater systems, both internal and external of the barrel, have been used to heat curling irons. [004] A curling iron that has a barrel formed from a round metal tube is known. An early patent for a curling iron, specifically U.S. patent no. 161,313 to Wilkinson, discloses a curling iron having long, hollow tapered barrel that is heated by a heat source external to and distinct from the curling iron.

[005] Curling irons that have a straight barrel made of elongated round metal tubing having a constant diameter are also known. Such cylindrical tube barrels having an uniform diameter are simple and inexpensive to manufacture.

[006] Important features of a curling iron are the shape and size of the mandrel or barrel, and the energy available at the mandrel or barrel for heating hair. The amount of energy available at the barrel depends on the heat retention and heat conducting properties of the materials used to make the barrel and the shape of the barrel. Also, the design and method of heating used by the curling iron's heater are important factors in determining the energy available for thermally heating the barrel of the curling iron.

[007] The radius of the curling iron barrel has a significant effect on the curling properties of the curling iron. A barrel that has a relatively small radius results in a tighter and longer lasting curl whereas a barrel that has a relatively large radius forms a looser curl (i.e., a more open curl or wave pattern) in hair being styled. Curling irons having a relatively large radius barrel may be used to iron (i.e., straighten) sections of hair. [008] Since the shape and size of the curling iron barrel largely determines the shape imparted to the hair being styled, several curling irons, each curling iron having a different sized radius barrel, may be used to achieve a desired hairstyle. However, using multiple curling irons is inconvenient and requires the expensive proposition of buying multiple curling irons.

J] U.S. patent no. 4,103,145 to Oliveri, and U.S. patent no. 3,922,521 to Viegut, both disclose a curling iron that has a pronounced forward tapering, conical barrel.

[0010] The Oliveri patent discloses a tapered barrel curling iron that is periodically heated by an external heat source. Since the curling iron is heated and then removed from the heat source before it is applied to the hair, the temperature of the curling iron is at a maximum temperature upon removal from the heat source. The temperature of the curling iron progressively decreases the all the while the curling iron is away from the heat source. The effective curling ability of such a curling iron is limited by the inconsistent and variable heating characteristics exhibited by the curling iron when it is removed from the heat source. The effectiveness and efficiency of such a curling iron is also limited by the inconvenience of constantly having to re-heat the curling iron by the external heat source.

[0011] The Olivieri patent also discloses a long clamp to hold hair in place along the barrel of the curling iron. The long clamp holds a starting section of hair between the clamp and the barrel. Subsequent windings of the hair are wound on top of the clamp and the barrel, locking the clamp against the barrel. Thus, the hair must be unwound to release the clamp. Unwinding the hair from the barrel reduces the set of the curl and the precision of the set. [0012] The Viegut patent discloses a corded electric curling iron having a conical barrel. The disclosed curling iron has a simple electric heater housed within the barrel of the curling iron. Viegut does not disclose the details of the heater. The heater is described as an electrical resistance rod and one or more electrical resistance coils. Viegut also discloses a simple circuit having a switch and a resistance heater in series with a voltage source. The switch is disclosed as a two-position slide switch. Viegut does not disclose how the temperature of the disclosed curling iron is or can be controlled.

[0013] The Viegut disclosed curling iron is also disclosed as having several rows of comb-like spines extending from the barrel thereof. The spines are provided to guide the hair about the barrel of the curling iron. The Viegut disclosed spines are not heated. Thus, the spines do not aid in transferring heat to the hair.

[0014] For a curling iron to perform effectively and reliably, the temperature of the barrel is generally desired to be between about 140D C and about 160D C. This temperature range accommodates a wide variety of variables, including differences in hair types and different methods of using the curling iron. The temperature range of 140D C and 160D C is, technically, a rather narrow window within which to maintain the temperature of the barrel. Maintaining the temperature of the barrel within the temperature range of 140° C and 160° C can be particularly difficult when a periodic heating method is used to heat barrel.

[0015] In a heating system using a periodic heating method, there is typically a tendency to initially heat the barrel to a very high maximum temperature, from which the barrel temperature will decrease until reheated to the maximum temperature. In this manner, the length of time required for the barrel to cool (i.e., the cooling curve) is prolonged. However, there is a danger in such a periodic heating method of overheating the curling iron barrel. An overheated barrel can easily damage the hair being styled.

[0016] Depending on the length of time of exposed to the heat, temperatures above 160° C can dry fine hair and make it brittle. Temperatures above about 170° C can burn and permanently damage hair. Temperatures above 180° C can melt hair and temperatures greater than about 180° C can start a fire.

[0017] Curling irons typically have a peak barrel temperature that is at or near 160° C, particularly if the heating system uses a periodic heating method to heat the barrel. The peak barrel temperature may be permitted to approach the maximum acceptable level in an attempt to maximize the length of effective working time for the curling iron (i.e., when the barrel temperature is between about 140° C and about 160° C).

[0018] The heat content of the barrel may be increased to effectuate a longer working time for a barrel that is heated by a periodic heating system. In general, increases to the heat content of the barrel encompass increasing the thermal mass of the barrel. However, increasing the thermal mass of the barrel typically results in increasing the weight of the barrel. Also, a curling iron that has a large thermal mass typically requires a relatively long time to heat to a desired high temperature.

[0019] A curling iron that has an electric heater lacking a temperature control will not function satisfactorily because of the unpredictable and intermittent temperature loading that is inherent in the styling of hair. Factors impacting the temperature loading of the curling iron include the hair being styled and the methods used in styling the hair. The hair can be wet or dry, and heavy or fine. Additionally, the curling iron may be used continuously with little or no time for the barrel temperature to sufficiently recover to a the desired high operating temperature. Also, an uncontrolled heat source can exceed critical, and even dangerous, temperatures.

[0020] Tubular-barreled curling irons have been made with thermostatic controls and with self-regulating ceramic heaters. Such systems are capable of avoiding the critically high temperatures that an unregulated system may encounter. However, such systems have difficulty in maintaining the temperature of the barrel within the narrow window of optimal performance, that is between the temperatures of about 140° C and about 160° C.

[0021] Therefore, there is a need for a curling iron that has a conical barrel that delivers a controllable and consistent heating of the conical barrel for effective and efficient styling of hair.

BRIEF SUMMARY OF THE INVENTION

[0022] It is an object of the present invention to provide a curling iron that effectively and efficiently styles hair.

[0023] It is another object of the present invention to provide such a curling iron that has conical barrel.

[0024] It is yet another object of the present invention to provide such a curling iron that has an adjustable conical barrel portion for varying the radius and/or length of the conical barrel. [0025] It is still another object of the present invention to provide such a curling iron that has a controllable, substantially constant heat output.

)26] It is a further object of the present invention to provide such a curling iron that has a precisely controllable heat output.

[0027] These and other objects and advantages of the present invention are provided by a curling iron including a conical barrel and a heater located in the conical barrel for providing thermal energy to heat the conical barrel. A precise heater assembly is provided for accurately controlling a heating temperature of the conical barrel. At least one heat sink forcibly holds a heater in the conical barrel and conducts the thermal energy from the heater to the conical barrel.

[0028] The precise heater assembly preferably controls the heating temperature of the conical barrel to consistently and accurately maintain the temperature of the conical barrel within a safe and effective operating range of temperatures. The curling iron preferably has a relatively short spring clamp. The curling iron preferably has at least one raised thermally conductive surface feature located on an outer surface of the conical barrel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a top view of a curling iron of the present invention;

[0030] Figure 2 is a side view of the curling iron of Figure 1 ; [0031] Figure 3 is a partial sectional side view of the curling iron of Figure 1 ;

J32] Figure 4 is a top view of another embodiment of the present invention that has with a full-length spring clamp;

33] Figure 5 is a side view of the curling iron of Figure 4;

[0034] Figure 6 is a top view of yet another curling iron of the present invention that has a short spring clamp and a ribbed barrel;

[0035] Figure 7 is a side view of the curling iron of Figure 6;

[0036] Figure 8 is a top view of still another curling iron of the present invention that has a short spring clamp and a spiral rib;

[0037] Figure 9 is a side view of the curling iron of Figure 8;

[0038] Figure 10 is an exemplary illustration of stacking cones for providing a curling iron that has a selectively variable conical barrel; and

[0039] Figures 11 a and 11 b depict an exemplary illustration of a telescoping conical barrel for providing a curling iron that has a selectively variable conical barrel. DETAILED DESCRIPTION OF THE INVENTION

[0040] Referring to the figures and, in particular, Figures 1 through 3, there is shown a curling iron generally represented by reference numeral 5. Curling iron 5 has a handle 10 for safely manipulating the curling iron, a conical barrel 15, and a spring clip connected to the curling iron. The spring clip is preferably pivotally connected to the curling iron at or near a junction of handle 10 and conical barrel 15. A cool tip 35 is provided at a distal end of conical barrel 15. Cool tip 35 preferably remains substantially cool during heated operation of the curling iron, thereby providing a safe and comfortable location for manipulating the curling iron in addition to handle 10. A support stand 40 selectively holds the curling iron offset from a support surface to maintain the heated conical barrel 15 away from the support surface.

[0041] Curling iron 5 preferably receives power from an electrical outlet via power cord 45. It should be appreciated that the curling iron may be powered by, for example, a battery or other suitable sources of electrical power.

[0042] Handle 10 is preferably thermally insulated from conical barrel 15 that is heated to style hair. Handle 10 preferably provides a substantial surface that can be grasped and manipulated (e.g., turned) during the styling of hair. Handle 10 may define a space on the interior thereof that can be used to house various components of the curling iron. Handle 10 can have a soft-grip covering and/or other features located in or on the handle to facilitate comfortable and practical manipulation of curling iron 5.

13] In an aspect of the present invention, conical barrel 15 preferably tapers from a proximal end located at or near the handle 10 of the curling to a distal end located at or near cool tip 35. Due to the taper of the conical barrel, the radius (e.g., a first radius) of the conical barrel 15 at or near the proximal end is greater than the radius (e.g., a second radius) of the conical barrel at or near the distal end of the conical barrel. Preferably, the transition in the size of the conical barrel's radius is substantially smooth and gradual. However, the conical barrel 15 may taper in a graduated, step-wise manner (not shown).

[0044] The taper of conical barrel 15 may extend substantially the entire length of curling iron 5 as shown in the figures included herewith or the taper of the conical barrel may only extend a portion of the length of conical barrel 15(not shown).

[0045] The conical barrel 15 can be made of any thermally conductive material compatible with the teachings of the present invention. The conical barrel is thermally conductive in order to transfer heat from a heater assembly 50 located in the curling iron to the hair being styled with the curling iron 5.

[0046] In another aspect of the present invention, the conical barrel can have one or more raised thermally conductive surfaces located thereon. Figures 6 and 7 show a number of exemplary raised thermally conductive surfaces located on conical barrel 215. Figure 6 is a top view of curling iron 205 and Figure 7 is a side view of curling iron 205. The raised thermally conductive surfaces are close-ended ribs 235 that encircle conical barrel 215. The close-ended ribs 235 facilitate the styling of hair by preventing hair wrapped around conical barrel 215 from freely sliding along and/or off of barrel 215. Close-ended ribs 235 can provide a benefit in styling of hair by imparting a particular shape to the hair by virtue of the shape, size, and location of the close-ended ribs 235. [0047] Figures 8 and 9 show an exemplary raised thermally conductive surface located on conical barrel 315. Figure 8 is a top view of curling iron 305 and Figure 9 is a side view of curling iron 305. The raised thermally conductive surface is a spiral rib 335 that encircles conical barrel 315 in a helix-like manner. The spiral rib 335 can facilitate styling of hair by preventing hair wrapped around barrel 315 from moving along and/or off of the barrel. Spiral rib 335 can also contribute to the styling of the styling hair due to the shape, size, and location of the spiral rib 335.

[0048] It should be appreciated that other types and styles of raised thermally conductive surfaces can be located on the conical barrel of the present invention without departing from the scope of the present invention. For example, a raised patterned surface(not shown) may be located on the conical barrel for imparting a decorative crimp or wave pattern onto hair heated by such a conical barrel.

[0049] In an aspect of the present invention, a precise heater assembly 50 is provided to improve the performance of the curling iron by accurately controlling the heating of the conical barrel 15. The precise heater assembly 50 is preferably controlled to heat conical barrel 5 to an operating temperature using a high initial power input that results in a fast initial heating of the curling iron. In this manner, curling iron 5 heats up to an operating temperature very quickly.

[0050] The heater assembly 50 preferably uses an electronic power regulation circuitry 95. The power regulation circuitry 95 may use, for example, either phase angle or pulse width modulation logic to regulate the output of the heater assembly 50. Power regulation circuitry 95 can provide an onboard electronic switching device. Power regulation circuitry 95 preferably has a micro-processor for controlling various functions of the heater assembly 50. Accordingly, power regulation circuitry 95 can cost- effectively provide a timed automatic safety shutoff. Also, the ability to accommodate various voltages without the need of external transformers or voltage regulators can be, preferably, incorporated into the power regulation circuitry 95.

[0051] The heater assembly 50, including power regulation circuitry 95, preferably includes logic for accurately and rapidly responding to varying temperature loads. That is, power regulation circuitry 95 monitors the temperature load placed on the curling iron 5 and responds to changes therein by adjusting the heating capacity output of the heater assembly 50. Thus, power regulation circuitry 95 can have various types of feedback, comparator, and/or logic circuitry to monitor and respond to the variable temperature loads the curling iron 5 is likely to be subjected to.

[0052] In an aspect of the present invention, the heating system provides a cost efficient and reliable heating source for the curling iron. Preferably, the heating system has a layered arrangement of mica insulating paper 60 around a resistance-wire wound heater card 55.

[0053] A layered arrangement of mica insulating paper 60 around a resistance-wire wound heater card 55 is known in tubular barreled curling irons. In tubular barreled curling irons the heater cards are generally thermally bound to the barrel with a pair of opposing "D" shaped springs. The "D" shaped springs compress the layers of the heater and conduct heat to the barrel.

[0054] Unique to the present invention is the heater assembly design shown in Figure 3. Heat sinks 65 are provided to locate or position the heater card 55, compress the heater card 55 and the heat sinks 65 into their respective desired locations, and conduct heat from the heater card 55 to the conical barrel 15. The heat sinks 65 have a generally half-moon shape. A rounded portion of the half-moon shaped heat sinks 65 is placed in conforming physical contact with an inside surface of the conical barrel 15. A flat side of the half-moon shaped heat sinks 65 is in physical contact with the heater card 55. Heat sinks 65 are preferably made of a metal, but may be made of any suitable thermally conductive material.

[0055] Heat sinks 65 are arranged and sized to forcibly press against the inside surface of the conical barrel 5 and against the surface of the heat card 55. Accordingly, heat sinks 65 locate and compress heat card 55 in a desired location and conduct heat from the heat card 55 to the conical barrel 5.

[0056] Due to the conical shape of conical barrel 5 and the complimentary shape of heat sinks 65, heat sinks 65 are preferably conical shaped. Heat sinks 65 therefore preferably have a large contact surface area with conical barrel 5 and the heater card 55. Accordingly, heat sinks 65 provide efficient and reliable contact between the electrical heat source, heater card 55, and the conical barrel 5. The conical shape of the barrel 5 is advantageously used to achieve a reliably tight thermal contact between the heater card 55, and the conical barrel. In this manner, the heater assembly 50 is made more efficient and cost-effective to operate.

[0057] The precise heater assembly 50 provides a curling iron that can operate safely in the optimal vicinity of the high temperature ceiling of the curling iron 5.

[0058] The heater assembly 50 provides a load responsive heating system and a consistent working temperature. The curling iron preferably has a selectively variable temperature operating window for providing precision temperature selection and operation within a narrow temperature range. The selectively variable temperature operating window can preferably be adjusted to correspond to a thermal load and hair type.

[0059] In one aspect of the present invention, electrical connections between insulated wire leads 75 and the heater card 55 are made at metallic eyelets 77 that are connected through the heater card 55. Also connected to the heater card 55 is a clamp or connector 85. The clamp or connector 85 locates and retains a thermal sensor 90. Thermal sensor 90 can be implemented, for example, as a negative temperature coefficient bead, a positive temperature coefficient bead, a transistor, or any similar electronic component that is characterized by a predictable and consistent change in electrical resistance (or other electrical and/or physical behavior) with respect to a temperature change. A preferred embodiment employs a negative temperature coefficient (NTC) sensor.

[0060] In one aspect of the present invention, the spring clamp 20 is provided for holding hair in physical contact with conical barrel 5. The spring clamp 20 is preferably relatively short compared to the overall length of the conical barrel 5, as shown in Figures 1 , 2, 3, 6, 7, 8, and 9. The spring clamp allows a tress or section of hair to be clipped to the conical barrel. The spring clamp may have a biasing member for selectively holding the hair against the spring clamp 20 (120, 220, and 320) in a desired location along the conical barrel 5 (115, 215, and 315).

[0061] The hair can be clipped, for example, to a larger diameter section of the conical barrel and wound towards a smaller diameter section of the conical barrel. In this manner, a curl in the shape of a spiraling helix can be easily and conveniently created using the present invention. Additionally, the raised thermal surfaces (e.g., 235 and 335) act to hold the hair in a desired position along the length of the conical barrel (e.g., 215 and 315).

[0062] Windings of hair subsequent to the initial winding of hair do not necessarily overlap onto or on top of the spring clamp due to the relatively short length of the spring clamp 20 (220 and 320). The spring clamp 20 (120 and 320) can be opened and the iron released from the hair and conical barrel 15 (215 and 315) without a need to unwind the hair from the conical barrel. Accordingly, tight, long lasting (i.e., harder) curls may set using the curling iron and clip provided by the present invention.

[0063] In an aspect of the present invention, the conical barrel, with or without raised ribs, has a sloping, tapered barrel. In one preferred embodiment, the conical barrel slopes from a radius of about 5/8 of an inch to about a radius of about 1/4 of an inch. Other useful slopes and starting diameters are contemplated and encompassed by the present invention. For example, a conical barrel sloping from a starting diameter of about one inch or 3/4 of an inch can slope or taper down to about 1/4 of an inch are within the scope of the present application. Other useful embodiments of the conical barrel are within the scope of the present invention such as, for example, a curling iron that has longer or shorter working lengths with steeper or flatter tapers than the specific examples discussed herein. The length of the conical barrel an the slope or taper of the barrel may be modified and adapted to facilitate different hair styling applications.

[0064] In another aspect of the present invention, the conical section of the barrel has a variable length and/or radius. For example, a number of nesting, complimentary shaped cones may be stacked one on top of other to selectively increase the effective radius of the barrel. Figure 10 illustrates an exemplary pair of nesting, complimentary shaped cones that may be stacked to vary the radius and length of the conical barrel. Conversely, the nesting, complimentary shaped cones my be un-stacked, one from on top of other, to selectively decrease the effective radius of the barrel, at least over a portion of the barrel's length.

ϊ@5] In yet another aspect of the present invention, the conical barrel be implemented as a conical, telescoping barrel. The radius and length of the taper of the conical, telescoping barrel may varied by varying the length of the barrel. Figures 11a and 11b illustrate such an example of a conical, telescoping barrel of the present invention. Figure 11a shows the conical, telescoping barrel in a compressed state whereas Figure 11 b shows the conical, telescoping barrel in an extended state.

[0066] In an aspect hereof, Figures 4 and 5 depict a top and a side view, respectively, of an embodiment of the curling iron hereof that has a long spring clamp.

[0067] It should also be appreciated by those skilled in the art that the particular curling iron functions and other aspects of the teachings herein are but examples of the present invention. Thus, they do not limit the scope or variety of applications that the present invention may be suitably implemented. Thus, it should be understood that the foregoing description is only illustrative of a present implementation of the teachings herein. Various alternatives and modification may be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the disclosure herein.

Claims

What is claimed is:

1. A curling iron comprising:

a conical barrel having an outer surface that tapers from a first radius to a second radius along at least a portion of a length thereof;

a heater assembly located in said conical barrel for providing thermal energy to heat said conical barrel;

a power regulation circuitry for controlling a heating temperature of said conical barrel; and

at least one heat sink for forcibly holding said heater in said location in said conical barrel and for conducting thermal energy from said heater to said conical barrel.

2. The curling iron of claim 1 , wherein said first radius is located at proximal end of said curling iron and said second radius at a distal end of said curling iron.

3. The curling iron of claim 1 , wherein said first radius is greater than said second radius.

4. The curling iron of claim 1 , wherein said length of said conical barrel is selectively variable.

5. The curling iron of claim 1 , wherein at least one of said first radius and said second radius is selectively variable.

6.The curling iron of claim 1 , further comprising a spring clamp having a length less than about 50% of said length of said conical barre

7. The curling iron of claim 6, wherein said length of said spring clamp is less than about 25% of said length of said conical barrel.

8. The curling iron of claim 1 , further comprising at least one thermally conductive raised surface on or projecting from said conical barrel.

9. The curling iron of claim 8, wherein said at least one thermally conductive raised surface is selected from the group consisting of: a close ended rib, a spiral rib, a raised patterned surface, or any combination thereof.

10. The curling iron of claim 1 , wherein said heat sink physically conforms to and contacts an inner surface of said conical barrel and physically contacts said heater assembly to conduct thermal energy therefrom to said conical barrel.

11. The curling iron of claim 1 , wherein said power regulation circuitry accurately maintains said heating temperature of said conical barrel between temperatures of about 140° C and about 160° C.