Patent application title:

AUTOMATIC HAIR CURLER HAVING MULTI-SIDED HEATING

Publication number:

US20260182716A1

Publication date:
Application number:

19/221,499

Filed date:

2025-05-28

Smart Summary: An automatic hair curler has a handle, a heating barrel, and a cylindrical wrapper that surrounds the barrel. The wrapper includes a clamping part that heats hair from both sides for better curling. It can rotate on its own to wrap hair around the barrel. Some parts of the clamping component can adjust automatically using springs. The wrapper connects to the handle with special conductors that ensure a stable power supply for heating. 🚀 TL;DR

Abstract:

In various embodiments, an automatic hair curling device includes a handle, a heating barrel, and a cylindrical hair wrapper that encases the barrel. The hair wrapper can include a clamping component that includes a heat-conducting part that presses against the heating barrel for dual-sided heating. The heating barrel and clamping component are each thermally coupled to separate heating elements. The cylindrical hair wrapper can rotate automatically for hair wrapping. Some examples of the clamping component can self-adjust through springs. In some embodiments, the cylindrical hair wrapper is electrically connected to the handle via ring-shaped conductor pairs. These conductors may include annular contact rails that maintain physical contact, with at least one rail having a warped section for improved connection stability. The rails may be made of elastic, electrically conductive materials. This electrical connection enables power delivery to a heating element in the cylindrical hair wrapper.

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Classification:

A45D1/04 »  CPC main

Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor with means for internal heating, e.g. by liquid fuel by electricity

A45D2001/002 »  CPC further

Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor Accessories therefor

A45D1/00 IPC

Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor

A45D1/00 IPC

Curling or holding the hair

Description

RELATED APPLICATION(S)

This application claims priority to Chinese Invention Patent Application No. 202411991001.7, titled “A Curling Iron,” filed on Dec. 31, 2024; to Chinese Utility Model Patent Application No. 202423321720.6, titled “Hair Curling Device,” filed on Dec. 31, 2024; and to Chinese Utility Model Patent Application No. 202520149853.5, titled “Automatic Hair Curler,” filed on Jan. 21, 2025; each of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

This disclosure relates generally to hair styling tools, and more particularly, to various features and designs of automatic hair curlers.

BACKGROUND

Hair curling irons are widely utilized for hairstyling purposes, particularly for creating curls and waves. Conventional curling irons are manually operated and typically include a cylindrical heating barrel with exposed heating surfaces. In use, a user manually wraps a section of hair around the barrel, maintains the position for a predetermined period, and subsequently unwinds the hair. This manual operation requires skill and precision to achieve consistent curls. The process can also be labor-intensive and may lead to wrist fatigue, particularly when styling an entire head of hair or working with long or thick hair. Furthermore, the exposure of the heated barrel poses a risk of burns and scalding.

To address these shortcomings, automatic hair curling irons have been developed. Such devices typically incorporate a motor-driven mechanism that automatically wraps a section of hair around the heating barrel, thereby reducing manual effort and mitigating the likelihood of user error. Once the curling process is complete, the device releases the hair. When compared to traditional manually operated curling irons, the automatic hair curling irons have higher efficiency.

Despite these advancements, existing automatic curling irons still have limitations. For example, one limitation is that the heating barrel primarily applies heat to only one side of the hair strand, leading to uneven heat distribution. Consequently, the curls produced may lack durability and fail to maintain their shape for a prolonged period. Accordingly, there remains a need for further technical advancements in automatic hair curling irons to enhance efficiency, safety, and the overall effectiveness of the curling process.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present disclosure are illustrated by way of example, not limitation, in the accompanying figures, where like references indicate similar elements.

FIG. 1 illustrates a perspective view of an example of an automatic hair curler in accordance with the present disclosure.

FIG. 2 illustrates an exploded view of the example automatic hair curler of FIG. 1.

FIG. 3A illustrates an example automatic hair curler having its protective cover removed.

FIG. 3B illustrates an example cross-section X-X′ of the embodiment of automatic hair curler shown in FIG. 3A.

FIG. 3C illustrates additional implementation details of the embodiment of automatic hair curler in FIG. 3B.

FIG. 4A illustrates an additional or alternative embodiment of a hair clamping component introduced here.

FIG. 4B illustrates different embodiments for implementing a tilt angle for the hair clamping component shown in FIG. 4A.

FIG. 4C illustrates an example interior view of a heating barrel of an automatic hair curler introduced here.

FIG. 5 illustrates a portion of an example hair wrapper where it includes a hair clamping component having a heat conducting surface.

FIG. 6 illustrates the example hair wrapper of FIG. 5 with its hair clamping component removed.

FIG. 7 illustrates an example of a hair clamping component having a heat conducting surface that is thermally coupled to a heating element.

FIG. 8 illustrates an example casing structure part for a hair clamping component introduced here, where the casing structure part includes a curved heat conducting surface and can house a second heating element.

FIG. 9 illustrates a heating element retainer that can be implemented to hold a heating element and an elastic device in their positions with respect to the casing structure part of FIG. 8.

FIG. 10 illustrates another perspective view of the example automatic hair curler of FIG. 3A, further with its hair wrapper removed.

FIG. 11 illustrates additional details of the perspective view shown in FIG. 10.

FIG. 12 illustrates an exploded view of an example automatic hair curler having its hair wrapper removed from the handle as well as showing a number of example ring-shaped electrical conductors, in accordance with the present disclosure.

FIG. 13 illustrates additional implementation details of the embodiment of automatic hair curler in FIG. 12.

FIG. 14 illustrates examples of ring-shaped electrical conductor pairs that are introduced here.

DETAILED DESCRIPTION

References in this description to “an embodiment,” “one embodiment,” or the like, mean that the particular feature, function, structure, or characteristic being described is included in at least one embodiment of the present disclosure. Occurrences of such phrases in this specification do not necessarily all refer to the same embodiment. On the other hand, the embodiments referred to also are not necessarily mutually exclusive.

As mentioned above, one drawback of conventional automatic hair curling irons is that they apply heat to only one side of the hair strand, thereby resulting in uneven heat distribution. This deficiency often leads to curls that lack longevity and fail to maintain their intended shape over an extended period. Heating hair from more than one side can help, but in order to achieve multi-sided (e.g., dual-sided) heating functionality, an additional heating element needs to be incorporated at a location separate from the primary heating barrel. It is observed in the present disclosure that a desirable solution is to integrate this additional heating element within the automatic hair wrapping mechanism to facilitate even heat application across the hair strand.

However, the integration of a second heating element into the hair wrapping mechanism presents its own technical challenges. The hair wrapper is a moving component that rotates around the heating barrel, thereby complicating the establishment of a stable and secure electrical connection. Moreover, heating elements typically require substantial power consumption, necessitating an electrical connection capable of delivering sufficient amperage while ensuring operational safety and device stability. The need to supply power to a rotating component while maintaining consistent heating performance further increases the complexity of the design.

In addition to the issue of uneven heat distribution, existing automatic hair curling irons also present other drawbacks. For example, conventional designs often expose users to an increased risk of scalding due to accidental contact with heated surfaces. Additionally, conventional automatic hair curling irons are susceptible to hair tangling and pinching within the rotating mechanism. Improper hair alignment or mechanical malfunctions may cause strands to become caught, leading to hair breakage, discomfort, or even device failure. Furthermore, prolonged exposure to high temperatures without adequate thermal regulation can result in excessive hair damage, including dryness and split ends.

Introduced here, therefore, are techniques that can be used to implement an improved automatic hair curling iron that provides dual-sided heating to enhance curl durability while simultaneously addressing concerns related to user safety, hair protection, and overall device reliability. According to the present disclosure, a hair curling device can include a handle, a heating barrel extending from the handle, and a cylindrical hair wrapper that encases or sleeves around the heating barrel. The cylindrical hair wrapper can include a hair clamping component with a heat conducting surface. At least one of the heating barrel or the cylindrical hair wrapper is rotatably mounted on the handle and configured to rotate automatically relative to the other. This rotation can wrap a section of hair around the heating barrel. During hair curling, the hair clamping component can press against the heating barrel, clamping part of the hair and heating it from both sides. In certain examples, the hair clamping component can self-adjust the hair clamping gap (e.g., using springs). In some embodiments, the heating barrel is thermally coupled to a first heating element, and the heat-conducting surface of the hair clamping component is thermally coupled to a second heating element that is separate from the first heating element. In one or more examples, the first heating element is housed inside the heating barrel, and the second heating element is at least partially housed within the cylindrical hair wrapper.

Further, in certain embodiments, the cylindrical hair wrapper is rotatably mounted on the handle. The cylindrical hair wrapper and the handle can be electrically connected through a number of ring-shaped electrical conductor pairs, where each pair provides a connection for one electrical polarity. In some embodiments, each ring-shaped electrical conductor pair includes two conductors. The two conductors can be positioned at respective ends between the handle and the cylindrical hair wrapper; for example, one conductor can be positioned on the handle, and another conductor can be positioned on the hair wrapper. The conductors each have an annular (or ring-shaped) contact rail. The annular contact rails, one on each conductor, are configured to face each other and maintain physical contact, thereby forming an electrical connection. In further embodiments, at least one of the annular contact rails includes a section that is warped, or bent, toward the other rail, which can improve connection stability. The contact surfaces of the rails, in some embodiments, are flat and can be made of elastic, electrically conductive material, such as copper or another suitable metal or alloy. In certain embodiments, the cylindrical hair wrapper and the handle are electrically connected to supply power to a heating element inside the cylindrical hair wrapper.

Overall, the embodiments of the present disclosure enhance hair curling efficiency by incorporating multi-sided (e.g., dual-sided) heating, an automated wrapping mechanism, and a stable electrical connection, ensuring even heat distribution, longer-lasting curls, and improved user safety.

In the following description, numerous specific details are set forth to provide a thorough understanding of the present disclosure. It will be apparent to one skilled in the art that the techniques introduced here may be practiced without these specific details. In other instances, well-known features, such as specific fabrication techniques, are not described in detail in order to not unnecessarily obscure the present disclosure. References in this description to “an example,” “one example,” or the like, mean that a particular feature, structure, material, or characteristic being described is included in at least one implementation of the present disclosure. Thus, the appearances of such phrases in this specification do not necessarily all refer to the same example. On the other hand, such references are not necessarily mutually exclusive either.

Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more examples. Also, it is to be understood that the various exemplary implementations shown in the figures are merely illustrative representations and are not necessarily drawn to scale.

The terms “coupled” and “connected,” along with their derivatives, can be used herein to describe structural relationships between components. It should be understood that these terms are not intended as synonyms for each other. Rather, unless otherwise made apparent in the context, the term “connected” may be used to indicate that two or more elements are in direct contact with each other (without other intervening elements between them). And, unless otherwise made apparent in the context, the term “coupled” can be used to indicate that two or more elements are in either direct or indirect (with other intervening elements between them) contact with each other, or that the two or more elements co-operate or interact with each other (e.g., as in a cause-and-effect relationship), or both. Notwithstanding the above, for purposes of this discussion, the term “electrical connection,” and its derivatives, merely refers to a general relationship in which objects are electrically coupled together such that electricity can flow through the coupling; it is not intended to specify the presence or absence of any intervening element.

FIG. 1 illustrates a perspective view of an example of an automatic hair curler 100 in accordance with the present disclosure. In accordance with the present disclosure, the example automatic hair curler 100 includes a handle 110, a heating barrel 120, a hair wrapper 130, and a protective cover 140. As shown in FIG. 1, the heating barrel 120 is arranged as an extension of the handle 110, along a general axis of the handle 110. According to some embodiments, the hair wrapper 130 is cylindrical in shape and, as shown in FIG. 1 for example, sleeves around (or encases) the heating barrel 120. The protective cover 140 is also generally cylindrical in shape and can sleeve around the hair wrapper 130.

FIG. 2 illustrates an exploded view of the example automatic hair curler 100 of FIG. 1. As shown in FIG. 2, the automatic hair curler 100 can include a number of example components, including the heating barrel 120 and the hair wrapper 130 already introduced above. The automatic hair curler 100 can further include a mounting column 122 for mounting the heating barrel 120, an electrical motor 172 for driving the automatic rotation for hair wrapping, as well as a transmission gear 176, a transmission ring 178, a first end cover 179, a second end cover 174, a controller module 150, a shell cover 164, and a bottom shell 162. The controller module 150 can be coupled to user interfaces and control buttons 152, 154, 156, and 158. Moreover, in the example shown in FIG. 2, the automatic hair curler 100 has a one-piece style protective shell that has a cylindrical protective cover part 142 as well as a handle part 144. However, it is not necessary to implement the cylindrical protective cover part 142 as well as the handle part 144 as one-piece. Note that, in both the embodiments shown in FIGS. 1 and 2, the automatic hair curler 100 is in a corded device and, as such, it includes a power cord 170 for connection to an external power source. However, in other embodiments, the automatic hair curler 100 can be implemented as a cordless device. In the cordless embodiments, the hair curler 100 can incorporate typical additional components to enable cordless operations, such as a rechargeable battery, a charging port, and a battery status indicator. Also, note that, for the simplicity of the discussion, unless it is made clear otherwise from the context, the following description assumes an example implementation where it is the hair wrapper 130 that is motorized and rotates around the heating barrel 120; however, a person having ordinary skill in the art will recognize that the techniques and features disclosed here are similarly applicable to those embodiments where it is the heating barrel 120 that is motorized and rotates around the hair wrapper 130, or those embodiments where both the heating barrel 120 and the hair wrapper 130 are motorized such that they rotate around each other in a relative manner.

Now, with simultaneous reference to FIGS. 1 and 2, the various features of the automatic hair curler 100 are explained in more detail below. As is introduced here, various embodiments of the automatic hair curler 100 are designed to simplify the hair curling process by incorporating an automatic rotation mechanism that eliminates the need for manual hair wrapping. Specifically, in some implementations, the automatic hair curler 100 can include a user interface that enables easy operation and allows users to access and adjust operational parameters. Example user interface may include a power button 152 that can be used to activate the automatic hair curler 100 (e.g., by pressing and holding the power button 152 for a predetermined amount of time, such as two seconds). In some embodiments, the power button 152 can also function as a control for changing temperature control settings so that the users can select a preferred heat level based on their hair type and styling needs. A display or a set of indicator lights 154 may be integrated to show the current temperature setting and operational status. In additional embodiments, directional control buttons 156 can allow the users to set the rotation of the cylindrical hair wrapper 130 in either a clockwise or counterclockwise direction, offering ease in achieving the functionality of symmetrical curls as well as flexibility in different curl styles. Finally, a rotate activation button 158 allows the users to start (and/or interrupt) the automatic hair curling process. In certain embodiments, the hair curler 100 may incorporate a timer function (e.g., in the controller module 150), which can enable users to customize the duration for which the hair remains wrapped around the heating barrel before being released. Additionally, or alternatively, the user interface may also include safety indicators or alerts, such as an automatic shutoff function after a period of inactivity.

The following is an example use case. After basic preparation of the hair (e.g., by brushing the hair to remove tangles) for curling, a user 102 can begin hair curling by powering up (e.g., via the power button 152) the automatic hair curler 100. In one or more examples, the hair curler 100 includes a temperature adjustment function, allowing the user 102 to select a desirable heat level for their hair type. Next, the user 102 chooses a bundle of hair 104 to be curled and places the bundle of hair 104 into an opening 122 located at the tip of the heating barrel 120. In one or more embodiments, the opening 122 is made of a material that is thermally insulative, which is different from the heating barrel 120. When the hair shafts are through the opening 122, the bundle of hair 104 falls through a U-shape inlet groove 137 arranged on the hair wrapper 130 and extends outward from the U-shape inlet groove 137, exiting the automatic hair curler 100, such as illustrated in FIG. 1. Thereafter, the user 102 activates the hair curler 100 (e.g., by pressing the rotate activation button 158). Upon activation, the hair wrapper 130 (e.g., in the embodiments where the hair wrapper 130 rotates as opposed to the heating barrel 120) rotates automatically around the heating barrel 120 in order to wrap the bundle of hair 104 around a heating surface of the heating barrel 120. The automatic rotation can ensure the uniform tension and distribution for consistent hair curls, thus making it achieve high quality results.

More specifically, the automatic hair curler 100 in the present disclosure includes the electric motor 172 that, depending on the implementation, can drive the rotation of either the heating barrel 120 (or, in other alternative embodiments, the cylindrical hair wrapper 130) to facilitate automatic hair wrapping. According to one or more embodiments, the controller module 150 is operably connected to the electrical motor 172 to control the rotational direction. In particular, the controller module 150 can direct the electric motor 172 to rotate the cylindrical hair wrapper 130 in a first direction to automatically wrap the bundle of hair 104 around the heating barrel 122. After wrapping, the controller module 150 can maintain the hair in position for a predetermined duration to allow for curling. Once the curling process is complete, the controller module 150 can cause an alert mechanism (e.g., which can be integrated with a circuit board that carries the controller module 150), such as an audible beep or a visual indicator, to notify the user 102 of the completion of the hair curling for the bundle of hair 104 so as to prompt the user 102 to continue with the next bundle of hair. In certain embodiments, the user 102 can adjust the time length for the hair curling, allowing further customization of curl tightness according to hair type and styling preference. Some embodiments also provide a control button (e.g., button 156) to allow the user 102 to set the rotational direction of the cylindrical hair wrapper, selecting between clockwise and counterclockwise rotation, e.g., for generating a symmetrical look for the hair curls on different sides or for additional styling options.

The disclosed automatic hair curler 100 can incorporate a number of safety features for user protection. In some embodiments, the automatic hair curler 100 can include an anti-pinch safety feature. In some examples, the controller module 150 can monitor the torque exerted by the electric motor 172 responsible for rotating the cylindrical hair wrapper 130, and the controller module 150 can control the electric motor 172 based on the torque that is detected. If the controller module 150 detects that the torque has exceeded a predetermined threshold, which can indicate potential resistance from trapped or excessively tensioned hair, the controller module 150 can automatically stop the electrical motor 172 to prevent further entanglement. This immediate cessation of movement helps protect the user's hair from being pulled or damaged while also preventing mechanical strain on the automatic hair curler 100. In addition, the automatic hair curler 100 may also include an alert mechanism, such as an audible beep or a visual indicator, to notify the user 102 when the anti-pinch function has been activated. In some further embodiments, when pinching or entanglement of hair is detected, the controller module 150 can reverse the direction of the electrical motor 172 to rotate the cylindrical hair wrapper 130 in the opposite direction, thereby untangling the hair. In several embodiments, the controller module 150 can have or be connected to one or more temperature sensors to regulate heat levels and reduce the risk of excessive exposure and heat damage to hair. In additional embodiments, the controller module 150 can also prevent overheating by implementing an automatic shut-off function when the controller module 150 detects the temperature of the automatic hair curler 100 exceeds a certain level. Some examples of the controller module 150 can also turn off the device after a predetermined period of inactivity.

The protective cover 140 can be made of thermally insulative materials to minimize heat transfer and enhance user safety during operation of the automatic curler device 100. Suitable materials may include, e.g., silicone, thermoplastic elastomers (TPE), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), phenolic resin composites, and so forth. Specifically, the example automatic hair curler 100 can include a one-piece protective cover (e.g., cover 140 in FIG. 1) that can include two portions, i.e., a protective sleeve portion 142 and a handle portion 144, such as shown in FIG. 2. The handle portion 144 can enable the user 102 to securely hold the hair curler 100, and the protective sleeve portion 142 can prevent the user 102 from accidental contact with heated components (which are discussed in more detail below) and mitigate the risk of scalding during use.

FIG. 3A illustrates an example automatic hair curler 300 (e.g., hair curler 100 of FIG. 1) having its protective cover (e.g., such as the protective cover 140) removed. FIG. 3B illustrates an example cross-section X-X′ of the embodiment of automatic hair curler 300 shown in FIG. 3A. FIG. 3C illustrates additional implementation details of the embodiment of automatic hair curler 300 in FIG. 3B. With simultaneous reference to FIGS. 3A, 3B, and 3C, the various features of the automatic hair curler 300 are explained in more detail below.

Similar to what is discussed above for automatic hair curler 100, the automatic hair curler 300 includes a cylindrical hair wrapper 330 surrounding a heating barrel 320. At least one of the heating barrel 320 or the cylindrical hair wrapper 330 is rotatably mounted on a handle 310 and configured for automatic relative rotation. (Note, however, that the embodiments shown here are ones with motorized cylindrical hair wrappers.) This rotation enables the automatic hair curler 300 to wind a bundle of hair around the heating barrel 320 in a controlled, automated manner.

One of the drawbacks mentioned above from the existing hair curling irons is that their heating barrel applies heat to only one side of the hair, which can lead to uneven heating and less durable curls. To address the limitation of single-sided heating, in accordance with the present disclosure, various embodiments of the automatic hair curler include multi-sided heating capability. In the embodiment shown the cross-section X-X', the cylindrical hair wrapper 330 includes a hair clamping component 332 coupled to a heating element 334, where the hair clamping component 332 is situated inside an installation slot 336. Note that, in one or more embodiments, this heating element 334 located on the hair wrapper 330 is separated and distinct from one or more heating elements that are in a conventional location (e.g., inside the heating barrel 320) in the hair curling device. As shown in FIG. 3B, the hair clamping component 332 further contains a number of heating element retainers 338 that can hold the heating element 334 in its position as well as function as positioning pins for a number of elastic devices 339 (e.g., cone-shaped coil springs). In addition, or as an alternative, to the heating element retainer 338, the heating element 334 can be secured using various suitable attachment techniques including, e.g., screwing, welding, clamping, or a removable connection.

According to the present embodiments, the hair clamping component 332 includes a heat conducting surface 333 (labeled in FIG. 3C) that is thermally coupled to the heating element 334. In one or more particular embodiments, the hair clamping component 332 is implemented as having a frame (e.g., which can be made of metal such as an aluminum alloy or another suitable type of thermally conductive material), and the heating element 334 can be positioned on the inner side of the frame so that the heat conducting surface 333 of the hair clamping component 332 is thermally coupled to the heating element 334. During the automated hair curling process, the hair clamping component 332 is configured to press against the heating barrel 320 (e.g., via the force exerted from the elastic devices 339), thereby securing at least a portion of the bundle of hair. As the automatic rotation takes place (e.g., with the hair wrapper 330), the hair clamping component 332 together with the heat conducting surface 333 rotates around the heating barrel 320. The motorized rotation of the hair wrapper 330 causes the bundle of hair to be wrapped around the heating barrel 320, which causes the side of the bundle of hair that faces the heating barrel 320 to be heated by the heating barrel 320; in the meantime, the same motorized rotation causes the heat conducting surface 333 to iron over the other side of the bundle of hair in a sweeping, circular motion. As a result, heat can be applied to the hair from both the heating barrel 320 and the heat conducting surface 333 of the hair clamping component 332, thereby promoting uniform heat distribution and improved curling performance.

In particular, in the embodiment shown FIG. 3C, a hair clamping gap 325 is formed between the heating barrel 320 and the heat conducting surface 333 (of the hair clamping component 332). In various embodiments, the hair clamping gap 325 can range from, e.g., 0.1 mm to 0.5 mm. Notably, the distance of the hair clamping gap 325 can be selected to suit the thickness of most typical hair strands such that the hair can remain effectively and securely retained within the hair clamping gap 325 during the hair curling process. Moreover, when the hair wrapper 330 rotates, the shape and configuration of the hair wrapper 330, along with the rotating motion, automatically cause the bundle of hair to be fed through the hair clamping gap 325. Specifically, consider that the hair needs to be securely clamped within the hair clamping gap 325 in order to be properly heated and curled, and yet not only the diameter of hair bundles varies among users, but also the volume of hair and the thickness of the hair section that goes through the hair clamping gap 325 for curling vary constantly. Therefore, in a plurality of embodiments, the hair clamping component 322 includes an adaptive mechanism such that the spacing of the hair clamping gap 325 can self-adjust in a dynamic manner (e.g., in response to the thickness of the hair that is fed through the hair clamping gap 325 in real-time) to ensure that hair is constantly, consistently, and properly secured.

According to a number of embodiments, this self-adjusting mechanism can be implemented in a number of ways. In one example, when hair is fed through the hair clamping gap 325 and applies pressure against the hair clamping component 332, the hair clamping component 332 faces a force that pushes it away in a direction from the heating barrel 320 and toward the installation slot 336 that houses the hair clamping component 332; therefore, as shown in FIG. 3C, an extra space can be arranged in the installation slot 336 such that when the hair clamping component 332 receives the force from hair being fed into the hair clamping gap 325, the hair clamping component 332 retracts into the extra space in the installation slot 336. The hair clamping component 332's casing and the heating element 334 can be held together by the heating element retainers 338, and the hair clamping component 332 can be installed into the installation slot 336. The heating retainer 338 can include a protruding tenon 338a as well as an elastic device positioning pin 338b. An elastic device 339, such as a cone-shaped coil spring, can be installed at the elastic device positioning pin 338b of a corresponding heating element retainer 338, so that the elastic device 339 pushes the hair clamping component 332 towards the direction of the heating barrel 320, thus generating a clamping force. The installation slot 336 includes a baffle plate 335, such as illustrated in FIG. 3C, so that when the hair clamping component 332 is pushed outward by the elastic device 339 toward the heating barrel 320, the baffle plate 335 functions as a limit when the protruding tenon 338a hits the baffle plate 335, preventing the hair clamping component 330 from popping out of the installation slot 336 completely. In this sense, the hair clamping component 332 is movably connected or movably attached to the hair wrapper 330, and the self-adjusting mechanism introduced here allows the hair clamping component 332 to move toward or away from the heating barrel 320 as the hair is fed through.

It is noted that the various details in the self-adjusting mechanism disclosed above are merely examples, as other implementations (or a combination thereof) can be suitable. For example, in another embodiment, a sliding connection can be implemented where the hair clamping component 332 can move along a sliding mechanism, e.g., a slider or roller, which can allow the hair clamping component 332 to travel along a track or guide rail arranged on the hair wrapper 330 in the direction of approaching or receding from the heating barrel 320. Alternatively, the hair clamping component 332 can be connected to the inner side of hair wrapper 330 via a hinge or a similar rotational connector, enabling self-adjustment of the hinge angle to dynamically change the distance of the hair clamping gap 325. Additionally, or alternatively, the hair clamping component 332 can be connected to the hair wrapper 330 through a telescopic mechanism, such as a telescopic rod or a compression spring, allowing for flexible adjustment of the hair clamping gap 325. Still, other possible connection methods for implementing an adjustable hair clamping gap (or for finetuning the distance thereof) can include magnetic attachment and/or a screw-adjustment mechanism.

FIG. 4A illustrates an example hair clamping component 432 introduced here according to an additional or alternative embodiment of the present disclosure.

Similar to what is introduced above, the automatic hair curler 400 illustrated in FIG. 4A includes a heating barrel 420, sleeved by a cylindrical hair wrapper 430, which is in turn covered by a protective cover 440. The cylindrical hair wrapper 430 of this automatic hair curler 400 also includes a hair clamping component 432 having a heat conducting surface 433. The heat conducting surface 433 is elongated and runs in the same direction as the handle (e.g. handle 110, not shown in FIG. 4A for simplicity), with one end of the heat conducting surface 433 closer to the handle (i.e., the proximal end) and the other end of the heat conducting surface 433 farther away from the handle (i.e., the distal end).

Specifically, the heat conducting surface 433 provided in the automatic hair curler 400 is elongated in shape and aligned with the handle, which is similar to what is discussed above.

However, it is observed that, when hair is fed into the hair clamping gap (e.g., gap 325, FIG. 3C), the root portion of hair enters the hair wrapper 432 first and remains at the upper section (or the distal end) of the heating barrel 420 while the end portion of the hair enters last and stays at the bottom section (or the proximal end) of the heating barrel 420. Yet, the hair strands have uneven thickness, where the hair ends are thinner while the hair roots are thicker. Accordingly, in a number of embodiments, the hair clamping component 432 is so configured so that one end of heat conducting surface 433 (referred to as the proximal end due to its proximity to the handle) is positioned closer to the heating barrel 430, while the other end (i.e., the distal end) of the heat conducting surface 433 is farther away from the heating barrel 430. As a result, as shown in FIG. 4A, the heat-conducting surface 433 is inclined at an angle (a) relative to the heating barrel 430. The tile angle a takes into consideration the uneven thickness of hair strands, where the hair ends are thinner while the hair roots are thicker, and therefore the implementation of this incline (or tilt) angle a can achieve better clamping of the hair as the hair is drawn into the hair clamping gap of the hair curler 400. This design can promote even and controlled heat distribution across the hair during the hair styling process.

FIG. 4B illustrates different embodiments for implementing a tilt angle for the hair clamping component shown in FIG. 4A. Recall that, as discussed above, to enhance the wrapping and ironing mechanism, the heat conducting surface 433 on the cylindrical hair wrapper 432 applies pressure toward the heating barrel 420 as the cylindrical hair wrapper 432 rotates. In some embodiments, this force is generated by multiple elastic devices 439a-439b, with at least one elastic device 439a positioned at the distal end of the heat conducting surface 433, and at least one elastic device 439b positioned at the proximal end of the heat conducting surface 433.

In one example implementation, shown as configuration (A) in FIG. 4B, the elastic components 439a-439b can differ in length, with the proximal end featuring a longer elastic device 439b than the distal end's elastic device 439a. This variation allows for differential pressure application, thus optimizing the hair wrapping process. This is also the configuration adopted in the embodiment of the automatic hair curler 400 shown in FIG. 4A. Alternatively, the stiffness of the elastic components may vary, where the proximal end's elastic device 439b can have a stiffer element than the distal end's elastic device 439a, so that the elastic force exerted by elastic device 439b is higher than that by the elastic device 439a when compressed by the same amount. This is shown as configuration (B) in FIG. 4B. This design can help the proximal end of the heat conducting surface 433 apply more resistance while the distal end remains more flexible, thereby accommodating different hair thicknesses. Additionally, the placement of the elastic devices 439a versus 439b may be asymmetrical, with the proximal end's elastic device 439b positioned closer to its corresponding edge at the proximal end of the heat conducting surface 433 while the distal end's elastic device 439a is set farther away from its corresponding edge at the distal end of the heat conducting surface 433. This is shown as configuration (C) in FIG. 4B. Depending on the field application, this asymmetric placement of springs may have less precise control over the pressure distribution but can be easier to manufacture.

In many embodiments, the heat conducting surface 433 (along with the heat clamping component 432 that carrying it) is also configured to retract into a space inside an installation slot 436 (e.g., slot 336, FIG. 3C) on the cylindrical hair wrapper 430 when pressure is applied by the hair being wrapped. To achieve the tilt angle a discussed here for the heat conducting surface 433, the proximal end of the hair clamping component 432 (and its heat conducting surface 433) can also be designed to retract more deeply into the wrapper 430 (or to become further away from the heating barrel 420) than the distal end. In some embodiments, this retraction depth variation can be achieved by implementing different depths in the space inside the installation slot 436 for the proximal and distal ends. This is shown as configuration (D) in FIG. 4B. Alternatively, the placement of baffle plates 435a-435b can be adjusted to control the retractable depth, limiting the movement of the hair clamping component 432 at the distal end more than at the proximal end. This option ensures a structured retraction mechanism and is shown as configuration (E) in FIG. 4B. Note that the placement of the baffle plates can be located inside the installation slot, at the opening of the installation slot, or outside the installation slot, in order to suit the application and design requirements.

FIG. 4C illustrates an example interior view of a heating barrel 420 that can be implemented with the automatic hair curlers introduced here. As shown in FIG. 4C, the embodiment of the heating barrel 420 can house one or more heating elements 422 inside the heating barrel 420. In certain specific embodiments, the heating barrel 420 is thermally coupled to a set of heating elements 422, and the heat conducting surface (e.g., surface 333) of the hair clamping component (e.g., component 332) is thermally coupled to yet another heating element (e.g., element 334) that is distinct from the heating elements 422. The heating elements 422 can be housed inside the heating barrel 422 to ensure direct internal heating. And, as already discussed above with respect to FIGS. 3A-3C, the separate heating element can be positioned externally to the heating barrel 420, e.g., at least partially housed within the cylindrical hair wrapper (e.g., wrapper 330). This dual heating configuration facilitates simultaneous heat application from both inner and outer surfaces of the wound hair section, which can lead to more efficient heat transfer, improved curl durability, and reduced styling time. It is noted that, although the mere notion of placing heating elements inside the heating barrel 420 may be conventional, the exact location and arrangement of the two heating elements (such as shown here in FIG. 4C) can still provide advantages over traditional configurations because the illustrated configuration promotes more even and quicker distribution of heat from the heating element 422 to the heating barrel 420.

FIG. 5 illustrates a portion of an example hair wrapper 530 where it includes a hair clamping component 532 having a heat conducting surface 533. FIG. 6 illustrates the example hair wrapper 530 of FIG. 5 with its hair clamping component 532 removed, thereby showing the installation slot 536. When the hair clamping component 532 is installed in the installation slot 536, a baffle plate 531 can confine the distal end of the hair clamping component 532 such that the hair clamping component 532 can have limited movement (such as to implement that self-adjusting mechanism for hair clamping gap, discussed above) while preventing the hair clamping component 532 from completely escaping the installation slot 536. Depending on the implementation, the installation slot 536 can either be directly recessed into the hair wrapper 530 or formed by at least two protruding partitions to create the enclosure on the inner surface of the hair wrapper 530. In this embodiment shown in FIG. 6, the base of the installation slot 536 is recessed relative to the surrounding inner wall of the hair wrapper 530 and enclosed by two protruding partitions, thereby creating a well-defined mounting space for the installation slot 536.

FIG. 7 illustrates an example of a hair clamping component 732 having a heat conducting surface 733 that is thermally coupled to a heating element 734 (which, according to one or more embodiments, is separate from heating elements for the heating barrel). The heating elements 734 are powered by electricity, which can be fed from the two heating element power pins 711. Particularly, the heating element 734 can generate heat when electrical power is received. In some embodiments, the heating element 734 is made of a positive temperature coefficient (PTC) material (whose resistivity increases with temperature), which is a type of thermistor that can heat up fairly quickly when powered. Suitable PTC materials can include ceramic-based compounds like barium titanate, polymer-based composites, and metal-based alloys such as nickel or tungsten compounds. This heat generated from the heating element 734 is then transferred to the heat conducting surface 733 as a part of the hair curling process.

Moreover, in the embodiments shown in FIG. 7, the elastic devices 739 are of a cone-shaped coil spring type. In some of these embodiments, the outer diameter of the cone-shaped coil springs can gradually increase from the heating element retainer 738 toward the base of the installation slot, such as illustrated in FIG. 7. Other types of elastic devices, such as a telescopic spring or a flat spring. It is noted that the selection of the spring type should take into account the installation space constraints needed, so that the self-adjusting mechanism can be as compact as practical while optimizing force distribution.

FIG. 8 illustrates an example casing structure part 731 for the hair clamping component 732. The heating element 734 is encased in the casing structure part 731 and retained in position by two heating element retainers 738. The casing structure part 731, together with the heating element retainers 738, can maintain a stable elastic connection between the elastic devices 739 and the hair clamping component 732. These components shown in FIG. 8 can be assembled together via screwing, clipping, stamping, or press-fitting, depending on the specific implementation requirements.

In addition, as shown in FIG. 8, certain embodiments of the heat conducting surface 733 can incorporate a curved heat conducting surface. Specifically, because the heating barrel is cylindrical (e.g., barrel 420, FIG. 4C), this curvature can enable the hair clamping component 732 to more effectively clamp the hair strands, thereby allowing clamping pressure to be more evenly distributed in the hair clamping gap (e.g., gap 325, FIG. 3C) between the heating barrel and the heat conducting surface 733. Further, in some embodiments, the heat conducting surface 733 can have a curvature greater than that of the heating barrel. In other words, the heat conducting surface 733 can have a curvature that is greater than a radian of the heating barrel. Because the hair clamping component 732 is positioned outside the peripheral of the heating barrel, the increased radius of the curvature of the heat conducting surface 733 can lead to a more consistent spacing between the hair clamping component 732 and the heating barrel, thereby improving the uniformity of contact with the hair.

The heat conducting surface 733 should have good thermal conductivity to effectively transfer heat. Therefore, in accordance with some embodiments, the casing structure part 731 is made of a thermally conductive metal material, e.g., copper, aluminum, or steel. It is noted that, however, for corrosion resistance, aluminum or aluminum alloys may be preferred.

FIG. 9 illustrates an example of the heating element retainer 738. In addition to holding the heating element 734 in position, embodiments of the heating element retainer 738 can further include protruding tenons 738a that can function together with baffle plates (e.g., baffle plate 335, FIG. 3C) so as to control the movement of the hair clamping component 732 within its installation slot (e.g., slot 536, FIG. 6).

Additionally, in some cases, the heating element retainer 738 includes elastic device positioning pins 738b so as to hold elastic devices 739 in their positions with respect to the casing structure part 731. Also, in certain examples, the heating element retainer 738 can include one or more grooves 438c, which can provide room for securing the necessary wiring for the heating element, further improving reliability.

FIG. 10 illustrates another perspective view of the example automatic hair curler 300 of FIG. 3A, further with its hair wrapper removed. FIG. 11 illustrates additional details of the perspective view shown in FIG. 10.

FIG. 12 illustrates an exploded view of an example automatic hair curler 1200 having its hair wrapper 1230 removed from its handle 1210 as well as showing a number of example ring-shaped electrical conductors 1280, 1285, 1290, and 1295, in accordance with the present disclosure. FIG. 13 illustrates additional implementation details of the embodiment of automatic hair curler 1200 in FIG. 12. FIG. 14 illustrates examples of one ring-shaped electrical conductor pair 1280, 1285 and another ring-shaped electrical conductor pair 1290, 1295. Various additional or alternative features of the example automatic hair curler 1200 are discussed below with simultaneous reference to FIGS. 12-14.

It is observed here that, during the hair curling process, power needs to be continuously supplied to the heating element on the hair wrapper 1230 while the hair wrapper 1230 rotates, and therefore a direct wiring approach is not suitable because it can lead to wire twisting and failure. To solve this issue, the present disclosure includes ring-shaped electrical conductors that are capable of being rotated while providing reliable electrical connections through direct physical and electrical contact. Generally speaking, the ring-shaped electrical conductors feature circular plates, with a first ring positioned outside a second ring, giving the first ring a larger diameter than the second. On a given end (e.g., either the hair wrapper end or the handle end), two ring-shaped conductors can be spaced apart, with one serving as the positive terminal and the other as the negative terminal. Similarly, on the opposite end, another two ring-shaped electrical conductors can follow a corresponding arrangement.

More specifically, in accordance with a number of embodiments disclosed here, the cylindrical hair wrapper 1230 is rotatably mounted on the handle 1210 of the automatic hair curler 1200. To maintain electrical connectivity between the handle 1210 and the cylindrical hair wrapper 1230, multiple pairs of ring-shaped electrical conductors are used. Each pair (e.g., conductor pair 1280, 1285, and conductor pair 1290, 1295) serves as a connection for a single electrical polarity, providing a stable power supply (e.g., to a second heating element 334 located on the hair clamping component 332 of the hair wrapper 330, FIG. 3B) as the cylindrical hair wrapper 1230 rotates.

As shown in FIG. 12, the bottom of the hair wrapper 1230 can include a first ring-shaped electrical conductor 1280 and a second ring-shaped electrical conductor 1290. These ring-shaped electrical conductors 1280 and 1290 are electrically connected to electrical wires to power the heating element on the hair wrapper 1230.

Correspondingly, on the top of the handle 1210 there can be a third ring-shaped electrical conductor 1285 and a fourth ring-shaped electrical conductor 1295 that are affixed to the handle 1210. The ring-shaped electrical conductor 1285 and 1295 on the handle 1210 then are electrically connected to a power supply 1270 and controlled by a control module 1250, which also controls the operation of the motor that is responsible for the automatic rotation of the cylindrical hair wrapper 1230. Each ring-shaped electrical conductor pair has two circular conductors, one positioned on the handle 1210 and the other on the cylindrical hair wrapper 1230. In other words, when assembled, the ring-shaped electrical conductor 1280 and the ring-shaped electrical conductor 1285 form an electrical conductor pair. Similarly, the ring-shaped electrical conductor 1290 and the ring-shaped electrical conductor 1295 form another electrical conductor pair. The conductors in a given conductor pair have annular contact rails that face each other and, when assembled, these annular contact rails in the conductor pair become in physical contact with each other, thereby maintaining a consistent electrical connection.

To enhance the stability of electrical connections, the present disclosure further includes a number of contact techniques that can be used between ring-shaped electrical conductor pairs. For example, in some embodiments, select portions of a given ring-shaped electrical conductor can be formed or bent as slightly rising toward its pairing ring-shaped electrical conductor, thus creating constantly elastic, physical contact.

Specifically, in some variations (e.g., shown in FIG. 14), at least one of the annular contact rails (e.g., of the ring-shaped electrical conductor 1295) includes a bent or warped section 1299 bulging toward the other annular contact rail (e.g., of the ring-shaped electrical conductor 1290), enhancing connectivity. Similarly, the annular contact rails of the ring-shaped electrical conductor 1285 also includes a bent or warped section 1289 bulging toward the other annular contact rail of the ring-shaped electrical conductor 1280.

Even further, in another embodiment, a given annular contact rail can feature two (or more) warped sections (e.g., sections 1289, 1299) on the contact rail's contact surface for improved electrical contact. In many of the embodiments, the plurality of warped sections is evenly spaced from each other so that the elastic pressure from the warped sections is evenly spread onto the corresponding contact rail of the ring-shaped electrical conductor in the pair. For example, in the illustration in FIG. 14, the contact rail of the ring-shaped electrical conductor 1285 includes two warped sections 1289 that are bent or bulging toward the conducting rail of the ring-shaped electrical conductor 1280, and the two warped sections 1289 are evenly spaced (e.g., located across) from each other on the contact rail of the ring-shaped electrical conductor 1285. Similarly, the contact rail of the ring-shaped electrical conductor 1295 includes two warped sections 1299 that are bent or bulging toward the conducting rail of the ring-shaped electrical conductor 1290, and the two warped sections 1299 are evenly spaced (e.g., located across) from each other on the contact rail of the ring-shaped electrical conductor 1295. According to one or more examples, the annular contact rails introduced here may be flat and may be made from elastic, electrically conductive materials to ensure durability and flexibility. In addition, or as an alternative, to the wrapped sections, small ball bearings can be added to improve the consistency of the connection. These further enhancements on the physical contact surface of the ring-shaped electrical conductors can help maintain reliable electrical contact during rotation.

Also, continuing with the above discussion, the ring-shaped electrical conductors 1280, 1285, 1290, and 1295 disclosed here can feature a number of wire connector fingers 1283, 1288, 1293, and 1298 where corresponding electrical wires (not shown for simplicity) can be securely attached. Further, to reinforce the mechanical stability of the ring-shaped electrical conductors 1280, 1285, 1290, and 1295 when installed, a number of installation tabs 1282, 1287, 1292, and 1297 can be included on the ring-shaped electrical conductors 1280, 1285, 1290, and 1295. Additionally, in one or more embodiments, these installation tabs 1282, 1287, 1292, and 1297 and the wire connector fingers 1283, 1288, 1293, and 1298 are evenly distributed on their corresponding conductors so that they promote mechanical stability. In this manner, the disclosed embodiments can help provide a stable power connection between the power supply and the heating element (that is in the rotating part of the hair curler, e.g., the cylindrical hair wrapper), thereby preventing wire interference or damage during the automatic rotation.

In the above-described manner, the disclosed automatic hair curler can improve heat distribution and curl durability by incorporating a multi-side (e.g., dual-sided) heating mechanism. In addition to a primary heating element, a secondary heating element can be integrated into, e.g., the rotating cylindrical hair wrapper, ensuring that heat can be applied evenly to both sides of the hair, as opposed to merely one side. The automatic hair curler can also feature a self-adjusting clamping mechanism with elastic components that adapt to different hair thicknesses, maintaining consistent pressure for uniform styling. The motorized rotation mechanism in the hair curler can wrap the hair automatically, reducing the need for manual handling and improving consistency. The disclosed embodiments can also incorporate safety features such as an anti-pinch function that stops the motor if excessive resistance is detected, a thermally insulated protective cover to minimize accidental burns, and an automatic shutoff for temperature control. To ensure a stable power connection while allowing rotation, certain embodiments of the hair curler utilize pairs of ring-shaped electrical conductors, thus eliminating the risk of wire tangling or breakage during the automatic rotation of the hair wrapper. Overall, the techniques and features introduced in the present disclosure can enhance the efficiency, reliability, and safety in the hair curling process for the automatic hair curler.

The foregoing description of various embodiments of the claimed subject matter has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed. Many modifications and variations will be apparent to one skilled in the art.

Embodiments were chosen and described in order to best describe the principles of the invention and its practical applications, thereby enabling those skilled in the relevant art to understand the claimed subject matter, the various embodiments, and the various modifications that are suited to the particular uses contemplated.

Although the Detailed Description describes certain embodiments and the best mode contemplated, the technology can be practiced in many ways no matter how detailed the Detailed Description appears. Embodiments may vary considerably in their implementation details, while still being encompassed by the specification. Particular terminology used when describing certain features or aspects of various embodiments should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the technology to the specific embodiments disclosed in the specification, unless those terms are explicitly defined herein. Accordingly, the actual scope of the technology encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the embodiments.

The language used in the specification has been principally selected for readability and instructional purposes. It may not have been selected to delineate or circumscribe the subject matter. It is therefore intended that the scope of the technology be limited not by this Detailed Description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of various embodiments is intended to be illustrative, but not limiting, of the scope of the technology as set forth in the following claims.

Claims

1. A hair curling device comprising:

a handle;

a barrel connected to the handle;

a cylindrical hair wrapper sleeving around the barrel, comprising a hair clamping component with a heat conducting surface; and

a second heating element to heat the heat conducting surface, wherein

during operation, the cylindrical hair wrapper and the barrel conduct a relative rotation with respect to each other to wind a strand of hair around the barrel, and the cylindrical hair wrapper heats and sweeps the strand of hair from an outside direction of the barrel during the relative rotation.

2. The device of claim 1, further comprising a first heating element to heat the barrel.

3. The device of claim 2, wherein the first heating element is housed inside the barrel, and the second heating element is housed outside the barrel.

4. The device of claim 1, wherein the second heating element is housed, at least partially, inside the cylindrical hair wrapper.

5. The device of claim 1, wherein

the cylindrical hair wrapper is rotatably mounted on the handle,

the cylindrical hair wrapper and the handle are electrically coupled through a plurality of ring-shaped electrical conductor pairs, and

each ring-shaped electrical conductor pair functions as a connection for one electrical polarity.

6. The device of claim 5, wherein

a given ring-shaped electrical conductor pair comprises two ring-shaped electrical conductors, each ring-shaped electrical conductor installed on a respective end between the handle and the cylindrical hair wrapper,

the two ring-shaped electrical conductors each have an annular contact rail, and

the two annular contact rails face each other and maintain physical contact with each other so as to establish electrical connection.

7. The device of claim 6, wherein at least one of the two annular contact rails has a warping part bulging toward the other annular contact rail.

8. The device of claim 6, wherein at least one of the two annular contact rails has a pair of warping parts bulging toward the other annular contact rail, the pair of warping parts evenly separated from each other on a contact surface.

9. The device of claim 6, wherein

contact surfaces of the two annular contact rails are flat, and

the two annular contact rails are made of elastic, electrically conductive materials.

10. (canceled)

11. The device of claim 5, wherein a given ring-shaped electrical conductor has one wire connection finger and a number of installation tabs, and

the wire connection finger and the number of installation tabs are evenly separated from each other on the given ring-shaped electrical conductor.

12. The device of claim 1, wherein

the heat conducting surface is elongated, extending along the same axis as the handle, the heat conducting surface having a proximal end and a distal end with respect to the handle, and

the proximal end of the heat conducting surface is closer to the barrel than the distal end of the heat conducting surface.

13. The device of claim 1, wherein the heat conducting surface is elongated, extending along the same axis as the handle, the heat conducting surface having a proximal end and a distal end with respect to the handle, and

the heat conducting surface of the cylindrical hair wrapper is configured to exert a force toward the barrel via a plurality of elastic devices, at least one elastic device of the plurality of elastic devices being mounted at the proximal end of the heat conducting surface, and at least one elastic device of the plurality of elastic devices being mounted at the distal end of the heat conducting surface.

14. The device of claim 13, wherein a length of the at least one elastic device at the proximal end of the heat conducting surface is longer than a length of the at least one elastic device at the distal end of the heat conducting surface.

15. The device of claim 13, wherein a stiffness of the at least one elastic device at the proximal end of the heat conducting surface is higher than a stiffness of the at least one elastic device at the distal end of the heat conducting surface.

16. The device of claim 13, wherein a distance-to-edge of the elastic device at the proximal end of the heat conducting surface is shorter than a distance-to-edge of the elastic device at the distal end of the heat conducting surface.

17. The device of claim 13, wherein the elastic devices comprise a cone-shaped coil spring or a telescopic spring.

18. The device of claim 1, wherein

the heat conducting surface is elongated, extending along the same axis as the handle, the heat conducting surface having a proximal end and a distal end with respect to the handle,

the heat conducting surface is configured to retract into the cylindrical hair wrapper in response to pressure from hair being automatically wrapped into the device, and

a retractable depth for the proximal end of the heat conducting surface is deeper than a retractable depth for the distal end of the heat conducting surface.

19. The device of claim 18, wherein

a deeper retractable depth for the proximal end of the heat conducting surface than the distal end is achieved by a different depth in an installation slot for the proximal end and the distal end of the hair clamping component.

20. The device of claim 18, wherein

a deeper retractable depth for the proximal end of the heat conducting surface than the distal end is achieved by a different positioning of corresponding baffle plates for the proximal end and the distal end of the hair clamping component.

21. The device of claim 1, wherein the heat conducting surface has a curvature smaller than a curvature of the heating barrel.

22. The device of claim 1, further comprising:

an electrical motor coupled to at least one of the barrel or the cylindrical hair wrapper to cause the relative rotation, and

a controller configured to control a rotatory direction of the electrical motor.

23. The device of claim 22, wherein the controller is configured to:

cause, via the electrical motor, the cylindrical hair wrapper to rotate in a direction relative to the barrel so as to automatically wrap the strand of hair around the barrel;

after the strand of hair is wrapped around the barrel, wait for a select amount of time for hair curling; and

after the strand of hair is curled, cause the device to notify a user of the device.

24. The device of claim 23, further comprising:

a first control button to control the direction to be either clockwise or counterclockwise; and

a second control button to control the select amount of time for hair curling.

25. The device of claim 22, wherein the controller is further configured to:

automatically stop the electrical motor when the controller detects that a torque from the electrical motor exceeds a predetermined value.

26. The device of claim 25, wherein the controller is further configured to:

in response to detecting that the torque exceeding the predetermined value, cause the electrical motor to counter rotate.

27. The device of claim 1, wherein the cylindrical hair wrapper is rotatable by an electrical motor.

28. The device of claim 1, further comprising:

a protective shell configured to sleeve around the cylindrical hair wrapper, wherein the protective cover is made of a thermally insulative material.

29. The device of claim 1, wherein a hair clamping gap is formed between the barrel and the heat conducting surface of the hair clamping component, the device further comprising:

a self-adjusting mechanism configured to adaptively adjust the hair clamping gap in response to a thickness of the strand of hair being fed through the hair clamping gap.

30. The device of claim 29, wherein the hair clamping gap ranges between 0.1 mm to 0.5 mm.

31. The device of claim 18, wherein the hair clamping component is configured to tilt toward the barrel at the proximal end with the proximal end closer to the barrel than the distal end to facilitate drawing hair into a hair clamping gap and an even heat distribution for the hair.