Anti-scald curling iron with thermal trigger self-locking structure

Abstract

The invention discloses an anti-scald curling iron with a thermal trigger self-locking structure, and belongs to the technical field of personal care electric appliances. The curling iron comprises a handle unit, a heating cylinder unit, a protective cover unit and a sliding rotary lock catch unit. The sliding rotary lock catch unit comprises a sliding track mechanism, a rotary trigger mechanism and a thermal trigger lock catch mechanism; the sliding rail mechanism achieves stable switching of the protective cover between the using position and the protective position. The rotary triggering mechanism guides the protective cover to rotate when the protective cover reaches the protective position; the thermal triggering lock catch mechanism automatically drives a spring bolt to complete locking at high temperature through a bimetal temperature-sensitive element; intelligent safety protection is achieved through thermal mechanical coupling, and the problem that a traditional protective cover is manually forgotten to be locked and the locking state is disjointed with the thermal risk of equipment, so that the scalding hidden danger is caused is solved.

Description

Technical Field

[0001] This invention relates to the field of personal care electrical appliances, specifically a heat-triggered self-locking curling iron designed to prevent burns. Background Technology

[0002] In the field of personal care appliances, curling irons are widely used due to their convenient styling functions. The core component of these products, the heating element, operates at high temperatures. To ensure safety, existing products typically have a sliding protective cover installed on the outside of the heating element. Currently, the protective covers on the market mainly employ two technical solutions: one is a simple push-pull structure that relies on a sliding track to switch positions, but lacks an effective locking function; the other uses a mechanical lock that requires manual operation to lock. However, these existing technical solutions have obvious shortcomings. First, the traditional sliding track and rotary triggering mechanism are independent of each other, resulting in cumbersome operation and complex structure. Second, the conventional locking mechanism relies entirely on the user's active operation, and it is easy to fail to lock due to negligence during actual use, which poses a serious safety hazard. More importantly, the existing protective cover connection structure only realizes the mechanical fixing function and fails to establish an effective correlation between the thermal state of the equipment and the safety locking mechanism. These technical defects result in inherent safety flaws in existing curling iron products; especially when users forget to lock them after use, the exposed high-temperature heating element can easily cause burns; therefore, there is an urgent need to develop a new locking structure that can automatically trigger locking based on the device temperature to achieve intelligent safety protection. Summary of the Invention

[0003] The purpose of this invention is to provide a heat-triggered self-locking curling iron that prevents burns.

[0004] The objective of this invention can be achieved through the following technical solutions: This invention provides a heat-triggered self-locking anti-scalding curling iron, comprising a handle unit, a heating cylinder unit, a protective cover unit, and a sliding rotating locking unit; The handle unit includes a housing 101, a power supply unit and a control circuit board disposed inside the housing, and the surface of the housing 101 is provided with a guide groove, a rotary guide groove and a locking groove. The heating element unit is fixedly installed at the front end of the handle unit, and includes a metal tube, an electric heating element disposed inside the metal tube, and a heat conduction end disposed at the base of the metal tube. The protective cover unit is slidably fitted onto the outside of the heating cylinder unit and is connected to the handle unit via the sliding rotary locking unit; The sliding rotary locking unit is used to achieve intelligent security protection, including: The sliding track mechanism guides the protective cover unit to slide axially along the heating cylinder unit by cooperating with the guide protrusion provided on the inner wall of the protective cover unit and the guide groove of the handle unit. The rotary triggering mechanism guides the protective cover unit to rotate by engaging with the limiting flange at the front end of the protective cover unit and the rotary guide groove of the handle unit. The guide groove extends axially, and the rotary guide groove is composed of a connected axial sliding section and a circumferential rotation section. The guide protrusion and the limiting flange are offset circumferentially from each other in the protective cover unit, and independently form a sliding fit with the guide groove and the rotary guide groove, respectively. The starting end of the rotary guide groove is smoothly connected to the end of the guide groove, so that the movement of the protective cover unit from the use position to the protection position is a continuous composite movement: In the first stage, the guide protrusion slides axially along the guide groove, at which time the limiting flange is located in the axial sliding section of the rotary guide groove, and the protective cover unit performs pure axial movement; when it slides to the end, it enters the second stage, and the limiting flange enters the circumferential rotation section of the rotary guide groove, forcing the protective cover unit to rotate circumferentially while being axially limited, until it reaches the locking preparation position. The heat-triggered locking mechanism includes a bimetallic temperature-sensitive element installed on the inner wall of the protective cover unit and thermally coupled to the heating cylinder unit, and a locking tongue linked with the bimetallic temperature-sensitive element. The locking tongue cooperates with the locking groove of the handle unit to complete locking when the protective cover unit is rotated to the locking preparation position. In the usage position, the protective cover unit retracts to expose the heating element unit; in the protective position, the protective cover unit extends forward and completely covers the heating element unit.

[0005] Preferably, the guide groove is an elongated groove extending axially along the handle unit housing 101; the rotary guide groove is a curved groove disposed on the front circumferential surface of the handle unit housing 101, and the starting end of the rotary guide groove is smoothly connected to the end of the guide groove; the locking groove is disposed on the front circumferential surface of the handle unit housing 101 and is a recess corresponding to the end position of the rotary guide groove.

[0006] Preferably, the guide protrusion of the sliding track mechanism has a trapezoidal cross-section, forming an anti-disengagement sliding pair with the guide groove; the guide groove is provided with limiting structures at both ends to limit the sliding stroke of the protective cover unit.

[0007] Preferably, the rotary triggering mechanism includes a rotary guide groove comprising an axial sliding section and a circumferential rotation section that are interconnected. The axial sliding section is parallel to and corresponds to the guide groove in the axial direction, serving as an auxiliary channel for the guide groove and providing a synchronous axial movement path for the limiting flange throughout the entire axial sliding stroke of the protective cover unit. Its length matches the sliding stroke of the protective cover unit. The circumferential rotation section is used to guide the limiting flange and the protective cover unit from axial movement to circumferential rotation at the end of the axial sliding. Its curvature is adapted to the rotation angle of the protective cover unit.

[0008] Preferably, the heat-triggered latching mechanism further includes a return spring, which is disposed between the latch and the inner wall of the protective cover unit. The return spring is used to provide auxiliary rebound force when the bimetallic temperature-sensitive element cools and resets, so that the latch can reliably disengage from the lock groove.

[0009] Preferably, the latch is connected to the bimetallic temperature-sensitive element via a lever transmission mechanism. The lever transmission mechanism includes a fixed fulcrum fixed to the inner wall of the protective cover unit and a lever that can rotate around the fixed fulcrum. The end of the lever near the bimetallic temperature-sensitive element forms a power arm and contacts the deformation driving end of the bimetallic temperature-sensitive element. The end of the lever near the latch forms a resistance arm and is hinged to the rear end of the latch. The lever transmission mechanism amplifies the deformation displacement of the bimetallic temperature-sensitive element and transmits it to the latch.

[0010] Preferably, the outer casing 101 further includes a manual unlocking mechanism for forcibly unlocking in an emergency: The manual unlocking mechanism includes an unlocking button located on the side of the handle unit, a push rod connected to the unlocking button, and a beveled top block located at the end of the push rod. The push rod is installed through a guide hole located inside the handle unit. The unlocking button is connected to the handle unit by a retaining claw on its side wall engaging with a slot in an opening in the side wall of the handle unit, and a button reset spring is provided inside. The push rod is arranged axially along the handle unit, with one end connected to the unlocking button and the other end having a beveled top block. A corresponding beveled surface is provided at the position of the latch, and the beveled top block and the beveled surface form a beveled sliding pair, which is used to convert the axial movement of the push rod into the radial displacement of the latch, forcibly driving the latch to disengage from the lock groove.

[0011] Preferably, the handle unit further includes an electronic status indication system for providing the user with clear feedback on locking and temperature status. The electronic status indication system includes an LED indicator, a latch position sensor, and the control circuit board. The LED indicator is disposed on the surface of the outer housing 101 of the handle unit and is electrically connected to the control circuit board via a circuit. The latch position sensor is installed inside the lock slot of the handle unit and is used to detect whether the latch of the heat-triggered locking mechanism has entered the lock slot, and sends the detection signal to the control circuit board. The control circuit board is configured to control the LED indicator to switch between different display states based on the received signal from the latch position sensor and the temperature signal from the temperature sensor, so as to indicate the locking and temperature status of the device to the user.

[0012] Preferably, the protective cover unit and the handle unit further include visual alignment marks for indicating the locked and unlocked states of the protective cover unit through the continuity and misalignment of visual patterns. The visual alignment markings include a first annular color band disposed at the tail edge of the protective cover unit and a second annular color band disposed at a corresponding position on the circumferential surface of the handle unit housing; when the protective cover unit is in the use position or the protective position but not rotated to the locking preparation position, the first annular color band and the second annular color band are misaligned with each other; when the protective cover unit is rotated to the locking preparation position, the first annular color band and the second annular color band are aligned circumferentially to form a continuous annular pattern, providing a visual indication of the locked state.

[0013] More preferably, the sliding rotary latch unit further includes a mechanical sound-generating component for producing a prompting sound when the latch engages with the lock groove, providing auditory status feedback: The mechanical sound-generating component includes an elastic steel sheet fixed to the inner wall of the protective cover unit and an impact protrusion disposed at the end of the rotating guide groove of the handle unit. When the protective cover unit rotates to the locking pre-position and the limiting flange reaches the end of the rotating guide groove, the elastic steel sheet moves to contact the impact protrusion, squeezes and generates elastic deformation until it slips and resets, generating a prompt sound by accumulating and releasing elastic potential energy.

[0014] The beneficial effects of this invention are as follows: This invention solves the burn hazard caused by human error in locking the curling iron and the disconnect between the locked state and the thermal risk of the device by integrating a heat-triggered self-locking mechanism, a sliding and rotating locking mechanism, and a multi-electronic status indication system. It utilizes the principle of thermomechanical coupling to coordinate the various mechanisms, achieving coordinated sliding, rotating, and automatic high-temperature locking of the protective cover, forming an intelligent safety protection mechanism. The heat-triggered locking mechanism ensures forced locking under high temperatures, the sliding and rotating locking unit achieves smooth switching and secure locking of the protective cover, and the electronic status indication system provides intuitive feedback on the locking status. This improves the inherent safety, operational reliability, and user experience of the curling iron while reducing the risk of burns, meeting the modern user's demand for safe and intelligent personal care tools. Attached Figure Description

[0015] To better understand and implement this invention, the technical solution is described in detail below with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the overall structure of the anti-scalding curling iron with a heat-triggered self-locking structure described in this invention; Figure 2 This is a detailed exploded view of the sliding rotary locking unit.

[0017] In the diagram: 1-Handle unit; 101-Outer shell; 102-Guide groove; 103-Rotating guide groove; 104-Locking groove; 2-Heating cylinder unit; 201-Metal tube; 202-Heat conduction end; 203-Heating element; 3-Protective cover unit; 301-Guide protrusion; 302-Limiting flange; 4-Sliding rotary locking unit; 401-Bimetallic temperature-sensitive element; 402-Lock tongue; 403-Reset spring; 404-Lever transmission mechanism; 5-Manual unlocking mechanism; 501-Unlock button; 502-Push rod; 6-Electronic status indication system; 601-Visual alignment mark. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, exemplary embodiments will be described in detail below, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of methods and systems consistent with some aspects of the present invention as detailed in the appended claims.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0020] The following detailed description of the specific implementation methods, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided in detail.

[0021] Example 1

[0022] Please see Figures 1-2 This embodiment provides a heat-triggered self-locking anti-scalding curling iron, including a handle unit 1, a heating cylinder unit 2, a protective cover unit 3, and a sliding rotating locking unit 4; The handle unit 1 serves as the main support and control unit of the device, employing an ergonomically streamlined outer shell 101. The outer shell 101 integrates a high-capacity power supply unit and an intelligent control circuit board. The power supply unit uses a rechargeable lithium polymer battery pack, enabling fast charging via a Type-C charging port located at the bottom. The control circuit board integrates a microprocessor, a temperature sensor, and a drive circuit, adjusting the operating power of the heating element unit 2 in real time by analyzing the temperature sensor signal. The outer shell 101 has precision-formed key structures for linkage and locking with the protective cover unit 3, specifically including two longitudinally extending guide grooves 102 that extend axially along the outer shell 101. The elongated groove, with a trapezoidal cross-section design, forms a sliding pair with the guide protrusion 301 of the protective cover unit 3 to prevent disengagement and locking; the rotary guide groove 103 is a curved groove set on the circumferential surface of the front end of the outer shell 101, which is smoothly connected by an axial sliding section and a circumferential rotation section. The beginning of the rotary guide groove 103 is smoothly connected to the front end of the guide groove 102, and is used to guide the protective cover unit 3 to complete the composite movement from axial sliding to circumferential rotation; the locking groove 104 is a recess set on the circumferential surface of the front end of the outer shell 101 and corresponding to the end position of the rotary guide groove 103, and is used to accommodate the locking tongue 402 of the heat-triggered locking mechanism in the locked state to form a locking fit; The control circuit board integrates a microprocessor, a temperature sensor, and a drive circuit, which together form the intelligent control core of the curling iron. The microprocessor uses a low-power microcontroller unit with a built-in analog-to-digital converter to run the temperature control algorithm and acts as the central control center to coordinate the logical actions between the heat-triggered latch, status indication, and heating unit. The temperature sensor uses a high-precision negative temperature coefficient thermistor attached to the heat conduction end 202 of the metal tube 201, which converts the physical quantity of temperature into an accurate resistance signal and feeds it back to the microprocessor in real time. The drive circuit, based on the pulse width modulation signal output by the microprocessor, precisely regulates the current flowing through the heating element 203 through a metal oxide semiconductor field-effect transistor power switch, thereby achieving rapid response and stable maintenance of the heating temperature. These three components form a closed-loop control, enabling the device to operate safely and efficiently at the set temperature and providing reliable data and triggering conditions for the heat-triggered latch mechanism. The handle unit 1 integrates a microprocessor and a temperature sensor, combined with a temperature control algorithm, to achieve multi-dimensional intelligent collaborative management of heating power, locking status, and user prompts. The system monitors the working temperature of the heating cylinder unit 2 in real time through the temperature sensor. The microprocessor, based on preset temperature control logic, precisely regulates the heating power through the drive circuit. When a high temperature is detected and the protective cover unit 3 reaches the protective position, it provides the necessary triggering conditions for the action of the heat-triggered locking mechanism. This collaborative control mechanism based on real-time temperature status perception enables the device to automatically enter and maintain the corresponding safety status in different usage scenarios. This embedded intelligent control system effectively solves the problems of traditional curling irons relying on manual operation, delayed safety protection, and inconsistent protection effects, and achieves precise, automated, and standardized management of the safety protection process.

[0023] The heating element unit 2 constitutes the core of the curling iron's heat output and is fixedly installed at the front end of the handle unit 1 via a precision threaded connection. The heating element unit 2 includes a metal tube 201, an electric heating element 203 disposed within the metal tube 201, and a heat conduction end 202 disposed at the base of the metal tube 201. The metal tube 201 is made of aerospace-grade aluminum alloy and manufactured through a precision extrusion molding process. The surface is anodized to form a wear-resistant and corrosion-resistant protective layer. The tapered structure design of the metal tube 201 achieves optimized heat conduction efficiency and uniform temperature distribution. The heat conduction end 202 is made of high thermal conductivity copper alloy and is connected to the base of the metal tube 201 with an interference fit to form an integral heat conduction structure, used to efficiently transfer heat from the heating area to the outside. The heating element 203 uses a high-resistance heating alloy wire as its heating core. The alloy wire is evenly wound around a ceramic skeleton with a precise pitch to form a stable heating circuit. The ceramic skeleton is coaxially positioned inside the metal tube 201 of the heating cylinder unit 2, and its two ends are precisely coaxially positioned with the metal tube 201 through high-temperature resistant insulating fasteners, so that the heating element is in an optimized heat conduction position inside the metal tube 201. The heating element 203 is surrounded by high-purity magnesium oxide powder as an insulating and heat-conducting medium, and the outermost layer is sealed with a stainless steel protective tube, forming a complete tubular heater structure. This multi-layer composite structure not only ensures excellent electrical insulation performance but also achieves high heat conduction efficiency, enabling the heating cylinder to quickly reach the set operating temperature and maintain stability. The heating element unit 2 achieves improvements in three key aspects through thermal management design: at the heat source construction level, the technical bottleneck of low heat conduction efficiency in traditional curling irons is solved through precise positioning of the ceramic skeleton and multi-layer composite encapsulation; at the heat distribution level, the problem of inconsistent styling effects caused by uneven axial temperature distribution is overcome by the optimized design of the conical metal tube 201; at the safety and coordination level, a reliable heat signal transmission path is established through direct thermal coupling between the heat conduction end 202 and the heat trigger locking mechanism, providing accurate thermal state information for the heat trigger locking mechanism, thus upgrading the heating unit from a simple heat energy output component to a comprehensive module that works in conjunction with the heat trigger locking mechanism.

[0024] The protective cover unit 3 is made of high-temperature resistant composite material and achieves its core protection function by being slidably fitted onto the outside of the heating cylinder unit 2. It is guided and restricted by the sliding and rotating locking unit 4 set on its inner wall and front end and handle unit 1. The inner wall of the protective cover unit 3 is provided with a guide protrusion 301 that cooperates with the guide groove 102 of the handle unit 1, and the front end is machined with a limiting flange 302 that forms a motion cooperation with the rotating guide groove 103. The cylindrical part of the protective cover unit 3 adopts a grid-like opening design, which effectively isolates the human body from contact with the high-temperature surface while ensuring sufficient heat dissipation. The rear edge of the protective cover is provided with a visual alignment mark 601 that cooperates with the electronic status indication system 6, and the status is visualized and managed through a high-contrast color band.

[0025] The protective cover unit 3 combines high-temperature resistant composite material with a grid-like opening, which solves the problem of low heat dissipation efficiency while providing heat insulation, avoiding the risk of material aging or burn-through caused by heat accumulation. The precise fit design of the guide protrusion 301 and the limiting flange 302 overcomes the operational pain points of traditional protective covers such as sliding jamming and poor rotation, and realizes a smooth switch between the use state and the protection state. Through the coordinated work with the sliding rotation locking unit 4 and the electronic status indication system 6, a reliable displacement, rotation, locking and indication linkage mechanism is established, which solves the safety hazards of unreliable protection and unclear status of traditional protective covers, and provides users with safety protection with visual and auditory feedback.

[0026] The sliding rotary locking unit 4 includes three cooperating sub-mechanisms: a sliding track mechanism that uses the guide protrusion 301 on the inner wall of the protective cover unit 3 to cooperate with the trapezoidal cross-section of the guide groove 102 of the handle unit 1 to achieve smooth axial movement of the protective cover between the use position and the protection position; the limiting structures at both ends of the guide groove 102 ensure that the sliding stroke of the protective cover unit 3 is always within the design range; a rotary trigger mechanism that uses the limiting flange 302 at the front end of the protective cover unit 3 to cooperate with the rotary guide groove 103; when the protective cover slides to the protection position, the limiting flange 302 moves from the axial sliding section to the circumferential rotation section, guiding the protective cover unit 3 to rotate to the locking preparation position; and a heat-triggered locking mechanism that uses the deformation of the bimetallic temperature-sensitive element 401 at high temperature to generate driving force; when the protective cover is in the locking preparation position, the deformation is amplified by the lever transmission mechanism 404 and drives the locking tongue 402 to move, so that the locking tongue 402 accurately engages with the locking groove 104 of the handle unit 1 to complete the final locking. The bimetallic temperature-sensitive element 401 adopts a composite layered structure, which is formed by combining a high expansion layer and a low expansion layer with significantly different thermal expansion coefficients through a high-temperature rolling process. One end of the bimetallic temperature-sensitive element 401 is fixed to the mounting base on the inner wall of the protective cover unit 3 by riveting, and the other free end is in contact with the power arm of the lever transmission mechanism 404. The installation position of the bimetallic temperature-sensitive element 401 forms a tight thermal coupling relationship with the heat conduction end 202 of the heating cylinder unit 2. When the ambient temperature reaches the preset trigger threshold, due to the difference in thermal expansion of the two metal layers, the element undergoes significant bending deformation towards the low expansion layer. By pushing the power arm, the lever transmission mechanism 404 rotates around the fixed fulcrum, and then the amplified displacement is transmitted to the locking tongue 402 through the resistance arm. After the temperature drops to a safe range, the bimetallic temperature-sensitive element 401 gradually returns to a flat state. At this time, with the assistance of the return spring 403, the entire transmission system is reset, and the locking tongue 402 reliably disengages from the locking groove 104, completing the unlocking process. The guide groove 102 is provided with limiting structures at both ends. The limiting structures are blocks integrally injection molded with the guide groove 102. They include a first limiting block located at the near end of the guide groove 102 and a second limiting block located at the far end. The first limiting block is used to limit the backward sliding stroke of the protective cover unit 3 to prevent the protective cover unit 3 from excessively retracting and leaving the working position. The second limiting block is used to limit the forward sliding stroke of the protective cover unit 3 so that the protective cover unit 3 accurately stops at the protective position that completely covers the heating cylinder. The height of the limiting block is the same as the depth of the guide groove 102, and its width is slightly larger than the width of the guide groove 102 to form a reliable mechanical stop surface. When the guide protrusion 301 of the protective cover unit 3 slides in the guide groove 102, the first limiting block prevents the guide protrusion 301 from sliding out of the rear end of the guide groove 102, while the second limiting block ensures that the guide protrusion 301 accurately stops at the preset protective position. This limiting structure design ensures the precise controllability of the sliding stroke of the protective cover unit 3 through mechanical hard limiting and eliminates the risk of mechanism damage or functional failure due to excessive sliding. The heat-triggered locking mechanism also includes a return spring 403 disposed between the locking tongue 402 and the inner wall of the protective cover unit 3. The return spring 403 provides an auxiliary rebound force when the bimetallic temperature-sensitive element 401 cools and resets, ensuring that the locking tongue 402 reliably disengages from the locking groove 104. The lever transmission mechanism 404 effectively amplifies the small deformation displacement of the bimetallic temperature-sensitive element 401. Its fixed fulcrum is disposed on the inner wall of the protective cover unit 3. The power arm is in contact with the deformation driving end of the bimetallic temperature-sensitive element 401, and the resistance arm is connected to the rear end of the locking tongue 402, forming an efficient and reliable power transmission system. The outer casing 101 also includes an electronic status indication system 6, which is located directly below the manual unlocking mechanism 5. This system provides clear locking status feedback to the user through multiple sensing channels. Specifically, visual alignment marks 601, located at the edge of the protective cover unit 3 and corresponding positions on the outer casing of the handle unit 1, employ a high-contrast color partitioning method. When the protective cover unit 3 is in the unlocked state, the marks display a continuous pattern; when the protective cover unit 3 is rotated to the locked position, the marks show a clear misalignment. A sound-generating component inside the handle unit 1 produces a prompt sound when the latch 402 engages with the lock groove 104, through the interaction of an elastic steel sheet and an impact protrusion. An LED indicator light on the surface of the handle unit 1 is connected to a control circuit board via wiring, switching the display status based on temperature sensor signals and the position signal of the latch 402. The curling iron is also equipped with a manual unlocking mechanism 5, including an unlocking button 501 on the side of the handle unit 1, a push rod 502 connected to the unlocking button 501, and a sloping top block at the end of the push rod 502. When an emergency unlock is required, pressing the unlocking button 501 drives the sloping top block through the push rod 502. The sloping sliding pair formed by the sloping top block and the corresponding sloping surface of the latch 402 converts the axial movement of the push rod 502 into the radial displacement of the latch 402, forcibly driving the latch 402 to disengage from the lock groove 104. The electronic status indication system 6 provides clear status feedback to the user through the misalignment display of the visual alignment mark 601, the prompt sound of the sound component, and the color change of the LED indicator: when the protective cover is rotated to the locked position, the visual mark is obviously misaligned, the elastic steel sheet interacts with the impact protrusion to produce a crisp prompt sound, and the LED indicator switches the display status according to the temperature sensor signal and the position signal of the latch 402. In the manual unlocking mechanism 5, the unlocking button 501 is installed at the opening on the side wall of the handle unit 1 via a snap-fit ​​structure. The snap-fit ​​structure includes elastic claws on both sides of the unlocking button 501 and corresponding slots on the edge of the opening on the side wall of the handle unit 1. The elastic claws adopt a cantilever beam structure with a specific barb angle. During assembly, they slide into the slots through elastic deformation and then return to their original shape to achieve a firm engagement. At the same time, it ensures that the unlocking button 501 moves smoothly along a predetermined trajectory during the pressing process. The snap-fit ​​structure also has a button return spring inside, which provides a stable rebound force for the unlocking button 501, so that the button can automatically return to the initial position after the press is released. The curling iron is equipped with a visual alignment mark 601 to provide an intuitive visual indication of the locked state. The visual alignment mark 601 is composed of a first annular colored strip located at the tail edge of the protective cover unit 3 and a second annular colored strip located at a corresponding position on the circumferential surface of the handle unit 1 housing. When the protective cover unit 3 is in the use position, or has slid to the protective position but has not yet been rotated to the locking preparation position, the first and second annular colored strips are misaligned in the circumferential direction to form a discontinuous pattern, clearly indicating the unlocked state. When the user rotates the protective cover unit 3 and makes it accurately reach the locking preparation position, the two annular colored strips are completely aligned in the circumferential direction to form a continuous and complete annular pattern, thereby providing the user with an intuitive visual confirmation that the locking preparation state has been entered. The curling iron integrates a mechanical sound-generating component to provide clear auditory feedback during the locking process. This component includes an elastic steel sheet fixed to a dedicated mounting base on the inner wall of the protective cover unit 3 via riveting, and a hemispherical impact protrusion integrally injection-molded with the outer shell of the handle unit 1 and precisely located at the end of the rotating guide groove 103. Its operation is as follows: when the protective cover unit 3 rotates to the locking pre-position and its front limiting flange 302 reaches the end of the rotating guide groove 103, the elastic steel sheet moves to contact the impact protrusion. As the rotation is completed, the impact protrusion compresses the elastic steel sheet, causing it to elastically deform and accumulate potential energy. Subsequently, the elastic steel sheet quickly slides off and resets, impacting the inner wall of the protective cover unit 3, instantly releasing the accumulated elastic potential energy to produce a crisp sound, audibly confirming that the mechanism is in place. The curling iron is also equipped with an electronic status indicator system 6 for providing intelligent status monitoring and display. The core of the electronic status indicator system 6 includes an LED indicator light on the surface of the handle unit 1, a latch 402 position sensor installed inside the locking groove 104 of the handle unit 1, a temperature sensor, and the control circuit board. The latch 402 position sensor is used to detect whether the latch 402 of the heat-triggered locking mechanism has entered the locking groove 104 and sends the detection signal to the control circuit board. The control circuit board is configured to perform a comprehensive logical judgment based on the received latch 402 position signal and temperature sensor signal, and control the LED indicator light to switch display states accordingly: when it is determined that the latch 402 is locked and the device is in a high-temperature state, the indicator light is solid red; when it is determined that the latch 402 is locked and the device temperature has dropped to a safe range, the indicator light is solid green; in other intermediate states or abnormal situations, the indicator light flashes orange, thereby providing the user with accurate and multi-dimensional device status information.

[0027] The sliding rotation locking unit 4, through the precise coordination of three sub-mechanisms, constructs a complete intelligent safety protection system, effectively solving the fundamental safety problems of traditional curling irons. The sliding rotation locking unit 4 organically integrates sliding, rotation, and heat-triggered locking, achieving a seamless one-click switch from the usage state to the safety protection state: the sliding track mechanism, through the cooperation of the trapezoidal cross-section guide groove 102 and the limiting structure, solves the problems of easy dislodgement and inaccurate stroke during the sliding of the protective cover; the rotation triggering mechanism, through the ingenious connection between the axial sliding section and the circumferential rotation section, overcomes the cumbersome operation of traditional protective covers requiring separate axial movement and rotation locking actions; the heat-triggered locking mechanism, through the coordinated work of the bimetallic temperature-sensitive element 401 and the lever transmission system, solves the safety hazards caused by human error in forgetting to lock, achieving automatic association between the device's thermal state and safety locking; this integrated design based on the principle of thermomechanical coupling ensures the forced locking of the protective cover under high-temperature conditions, and further provides users with reliable triple protection through the inherent safety characteristics of the mechanical structure, improving the product's safety performance and ease of use.

[0028] Example 2

[0029] This embodiment details the operation of the anti-scalding curling iron with a heat-triggered self-locking structure in Embodiment 1, demonstrating how to achieve a fully automatic transition from the usage state to the safety protection state.

[0030] The operator first performs a pre-use inspection of all components of the curling iron; after confirming that the protective cover unit slides smoothly and the heating element unit is working properly, the power is turned on; at this time, the control circuit board starts a self-test program, the temperature sensor begins monitoring the initial temperature, and the LED indicator shows the standby status. After confirming that everything is correct, the operation enters the normal working preparation state.

[0031] During use, the heating element unit starts working after the curling iron is powered on; the heating element heats up rapidly under the precise control of the drive circuit, and the heat is evenly distributed through the metal tube; the user holds the handle unit and brings the retracted protective cover unit into contact with the hair for styling; at this time, the guide protrusion of the protective cover unit is located at the rear end of the guide groove, the limiting flange is located at the end of the axial sliding section of the rotating guide groove, the locking tongue disengages from the locking groove, and the entire mechanism is in a freely sliding state of use.

[0032] After the shaping operation is completed, the user enters the safety protection process. Push the protective cover unit forward, so that the protective cover unit slides along the axis of the heating cylinder unit; the guide protrusion of the protective cover unit moves smoothly forward in the trapezoidal section of the guide groove until it is precisely blocked by the second limiting block at the front end of the guide groove. At this time, the protective cover completely covers the heating cylinder and reaches the protective position; at the same time, the limiting flange at the front end of the protective cover unit moves synchronously to the end of the axial sliding section of the rotating guide groove, preparing for the subsequent rotation action.

[0033] During the rotation triggering phase, the user rotates the protective cover unit; the limiting flange smoothly transitions from the axial sliding section to the circumferential rotation section, guiding the protective cover unit to complete a predetermined angle of rotation relative to the handle unit; when rotated to the locking preparation position, the limiting flange reaches the end of the rotation guide groove, the locking tongue is precisely aligned with the locking groove on the handle unit, and the locking mechanism enters the ready-to-trigger state.

[0034] During the heat-triggered locking phase, the intelligent control system and the status indication system work together. If the heating element is at a high temperature, heat is effectively transferred to the bimetallic temperature-sensitive element through the heat conduction end. When the protective cover unit is in the locking preparation position, the bending deformation of the bimetallic temperature-sensitive element after being heated is amplified by the lever transmission mechanism and drives the bolt to pop out radially, accurately locking into the lock groove to complete the automatic locking. During this process, the status indication system is activated synchronously through multiple sensing channels: the first and second annular color bands of the visual alignment mark are precisely aligned in the circumferential direction to form a continuous annular pattern, providing visual confirmation of locking. At the same time, the elastic steel sheet of the mechanical sound-generating component interacts with the impact protrusion located at the end of the rotating guide groove, undergoing contact, compression, deformation, and slippage reset, emitting a crisp prompt sound. Almost at the same moment, the bolt position sensor installed inside the lock groove detects that the bolt is in place. After comprehensively judging the locking signal and the high temperature signal, the control circuit board controls the LED indicator to turn red and stay on, clearly indicating that the high temperature has locked the state.

[0035] During the cooling phase of the device, after the curling iron is powered off and naturally cools to a safe temperature, the bimetallic temperature-sensitive element gradually returns to a flat state; the locking tongue reliably disengages from the locking groove under the auxiliary rebound force of the return spring, completing automatic unlocking; at this time, the control circuit board judges the status change according to the sensor signal and controls the LED indicator to switch to a solid green light, indicating that the device is ready to be unlocked after cooling; the user can rotate the protective cover unit in the opposite direction to make the limiting flange retract from the circumferential rotation section to the axial sliding section, and then slide the protective cover back to the use position.

[0036] In emergency situations, users can operate the manual unlocking mechanism; pressing the unlock button drives the inclined block via a push rod, and the inclined sliding pair converts the axial movement into radial displacement of the bolt, forcibly driving the bolt out of the lock groove; the unlock button automatically resets under the action of the internal button reset spring; this mechanical backup mechanism ensures safe unlocking under any abnormal conditions.

[0037] This embodiment details the entire process of a curling iron, from preparation, use, protection to unlocking, showcasing the collaborative working mechanism of each functional unit: the handle unit provides the foundation for intelligent control, the heating element unit achieves precise thermal management, the protective cover unit constructs a physical protective barrier, and the sliding and rotating locking unit enables automatic state switching. This integrated design based on the principle of thermomechanical coupling effectively solves the technical problems of traditional curling irons, such as reliance on manual operation, delayed safety protection, and unclear status indications, providing a safe, intelligent, and reliable solution for personal care appliances.

[0038] Example 3

[0039] This embodiment focuses on structural optimization design of the manual unlocking mechanism. The difference from Embodiment 1 lies in the adoption of a highly integrated, one-piece unlocking mechanism. Specifically, it includes: The original separate components of the unlocking button, push rod, and inclined top block are replaced by an integrally injection-molded unlocking lever. The lever is mounted on a bearing seat on the side wall of the handle unit via a stainless steel shaft. The inner end is integrally molded with an inclined top block structure, and the outer end is equipped with anti-slip texture to increase friction and facilitate operation. In terms of the transmission mechanism, the multi-stage transmission chain is eliminated, and a direct-acting design is adopted. When a 5N force is applied to the outer end of the lever, the lever rotates around the shaft, and the rotational motion is directly converted into the radial displacement of the locking tongue through the inclined joint. The reset system uses a piano wire torsion spring fitted onto the shaft. The two ends of the torsion spring are fixed to the lever slot and the positioning post on the inner wall of the handle unit, respectively, to achieve stable reset. In terms of installation, flat-head screws are used to fix the lever to the reinforcing rib on the inner wall of the handle unit through the two M2 threaded mounting holes of the lever base, improving installation accuracy and structural stability. This optimized solution reduces the number of parts and simplifies the assembly process. While maintaining the same unlocking performance, it significantly reduces manufacturing costs and assembly complexity, while improving the durability of the mechanism and the user experience.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An anti-scald curling iron having a heat-triggered self-locking structure, characterized in that, It comprises a handle unit (1), a heating cylinder unit (2), a protective cover unit (3) and a sliding and rotating lock unit (4). The handle unit (1) comprises an outer shell (101), a power supply unit and a control circuit board arranged in the shell, and the outer shell (101) is provided with a guide groove (102), a rotating guide groove (103) and a lock groove (104) on the surface. The heating cylinder unit (2) is fixedly installed at the front end of the handle unit (1) and comprises a metal pipe body (201), an electric heating element (203) arranged in the metal pipe body (201), and a heat conduction end (202) arranged at the base of the metal pipe body (201). The protective cover unit (3) is slidably sleeved on the outside of the heating cylinder unit (2) and is connected with the handle unit (1) through the sliding and rotating lock unit (4). The sliding and rotating lock unit (4) is used for realizing intelligent safety protection and comprises: A sliding rail mechanism is arranged on the inner wall of the protective cover unit (3) and cooperates with the guide groove (102) of the handle unit (1) to guide the protective cover unit (3) to slide along the heating cylinder unit (2) in the axial direction. A rotating trigger mechanism is arranged on the front end of the protective cover unit (3) and cooperates with the rotating guide groove (103) of the handle unit (1) to guide the protective cover unit (3) to produce rotating movement. The guide groove (102) extends in the axial direction, the rotating guide groove (103) is composed of an axial sliding section and a circumferential rotating section which are connected, the guide protrusion (301) and the limiting flange (302) are arranged in the circumferential direction of the protective cover unit (3) and are separately and independently formed in sliding cooperation with the guide groove (102) and the rotating guide groove (103), respectively, the starting end of the rotating guide groove (103) is smoothly connected with the end of the guide groove (102), and the movement of the protective cover unit (3) from the use position to the protection position is a continuous composite movement: in the first stage, the guide protrusion (301) slides in the axial direction along the guide groove (102), at this time, the limiting flange (302) is located in the axial sliding section of the rotating guide groove (103), and the protective cover unit (3) moves in the axial direction only; when sliding to the end, the limiting flange (302) enters the circumferential rotating section of the rotating guide groove (103), so that the protective cover unit (3) rotates in the circumferential direction while being limited in the axial direction until reaching the locking preparation position; A heat trigger lock mechanism comprises a bimetallic temperature-sensitive element (401) installed on the inner wall of the protective cover unit (3) and thermally coupled with the heating cylinder unit (2), and a lock tongue (402) linked with the bimetallic temperature-sensitive element (401), the lock tongue (402) cooperates with the lock groove (104) of the handle unit (1) to complete the locking when the protective cover unit (3) rotates to the locking preparation position. In the use position, the protective cover unit (3) is retracted to expose the heating cylinder unit (2); in the protection position, the protective cover unit (3) is extended forward and completely covers the heating cylinder unit (2).

2. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that: The guide groove (102) is an elongated groove extending axially along the outer shell (101) of the handle unit (1); the rotation guide groove (103) is a curved groove provided on the circumferential surface of the front end of the outer shell (101) of the handle unit (1), the starting end of the rotation guide groove (103) is in smooth communication with the end of the guide groove (102); the lock groove (104) is a recess provided on the circumferential surface of the front end of the outer shell (101) of the handle unit (1) and corresponding to the end position of the rotation guide groove (103).

3. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that: The guide protrusion (301) of the sliding rail mechanism has a trapezoidal structure in cross section, and forms a anti-disengagement sliding pair with the guide groove (102); the guide groove (102) is provided with a limiting structure at both ends for limiting the sliding stroke of the protective cover unit (3).

4. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that: The rotation guide groove (103) in the rotation trigger mechanism includes an axial sliding section and a circumferential rotating section in communication with each other; The axial sliding section is parallel and corresponding to the guide groove (102) in the axial direction, serving as an auxiliary channel of the guide groove (102) to provide a synchronous axial movement path for the limiting flange (302) during the entire axial sliding stroke of the protective cover unit (3), and the length thereof matches the sliding stroke of the protective cover unit (3); the circumferential rotating section is used to guide the limiting flange (302) and the protective cover unit (3) to convert from axial movement to circumferential rotation when the axial sliding ends, and the arc thereof is adapted to the rotation angle of the protective cover unit (3).

5. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that: The heat trigger lock mechanism further includes a return spring (403) arranged between the lock tongue (402) and the inner wall of the protective cover unit (3), which provides an auxiliary spring force when the bimetallic temperature-sensitive element (401) cools down, so that the lock tongue (402) reliably disengages from the lock groove (104).

6. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that: The lock tongue (402) is connected to the bimetallic temperature-sensitive element (401) through a lever transmission mechanism (404), which includes a fixed fulcrum fixed to the inner wall of the protective cover unit (3), a lever rotatable about the fixed fulcrum, an end of the lever near the bimetallic temperature-sensitive element (401) forming a power arm and contacting a deformation driving end of the bimetallic temperature-sensitive element (401), an end of the lever near the lock tongue (402) forming a resistance arm and hinged to the rear end of the lock tongue (402), and the lever transmission mechanism (404) amplifying the deformation displacement of the bimetallic temperature-sensitive element (401) and transmitting it to the lock tongue (402).

7. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that: The outer shell (101) further includes a manual unlocking mechanism (5) for forcibly releasing the lock in emergency situations. The manual unlocking mechanism (5) comprises an unlocking button (501) arranged on the side of the handle unit (1), a push rod (502) connected with the unlocking button (501), and an inclined top block arranged at the end of the push rod (502), wherein the push rod (502) is installed through a guide hole arranged in the handle unit (1); the unlocking button (501) is connected with a clamping groove in the side wall opening of the handle unit (1) through the elastic clamping jaws on the side wall, and a button reset spring is arranged in the unlocking button (501); the push rod (502) is arranged in the axial direction of the handle unit (1), one end of the push rod (502) is connected with the unlocking button (501), and the other end of the push rod (502) is provided with the inclined top block; a matching inclined surface is arranged at the corresponding position of the lock tongue (402), and the inclined top block and the matching inclined surface form an inclined surface sliding pair, which is used for converting the axial movement of the push rod (502) into the radial displacement of the lock tongue (402) and forcibly driving the lock tongue (402) to be separated from the lock groove (104).

8. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that, The handle unit (1) further comprises an electronic state indicating system for providing clear locking and temperature state feedback to the user. The electronic state indicating system comprises an LED indicating lamp, a lock tongue (402) position sensor, and the control circuit board; the LED indicating lamp is arranged on the surface of the outer shell (101) of the handle unit (1) and is electrically connected with the control circuit board through a line; the lock tongue (402) position sensor is installed in the lock groove (104) of the handle unit (1) and is used for detecting whether the lock tongue (402) of the heat-triggered lock catch mechanism enters the lock groove (104) and sending a detection signal to the control circuit board; the control circuit board is configured to control the LED indicating lamp to switch different display states according to the signal received from the lock tongue (402) position sensor and the temperature signal from the temperature sensor, so as to indicate the locking and temperature state of the device to the user.

9. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that, The protective cover unit (3) and the handle unit (1) further comprise visual alignment marks (601) for indicating the locking and unlocking state of the protective cover unit (3) through the continuous and dislocation of the visual patterns: The visual alignment marks (601) comprise a first annular color band arranged at the tail edge of the protective cover unit (3) and a second annular color band arranged at the corresponding position of the circumferential surface of the outer shell of the handle unit (1); when the protective cover unit (3) is in the use position or the protection position but has not been rotated to the locking preparation position, the first annular color band and the second annular color band are dislocated with each other; when the protective cover unit (3) is rotated to the locking preparation position, the first annular color band and the second annular color band are circumferentially aligned, forming a continuous annular pattern, thereby providing visual indication of the locking state.

10. The anti-scald curling iron with a thermal trigger self-locking structure according to claim 1, characterized in that, The sliding rotary lock catch unit (4) further comprises a mechanical sound producing assembly for producing a prompt sound when the lock tongue (402) is clamped into the lock groove (104), thereby providing auditory state feedback. The mechanical sound generating assembly comprises an elastic steel sheet fixed to the inner wall of the protective cover unit (3) and a striking protrusion arranged at the end of the rotation guide groove (103) of the handle unit (1); when the protective cover unit (3) rotates to a locking preparation position and the limiting flange (302) reaches the end of the rotation guide groove (103), the elastic steel sheet moves to contact, extrude and elastically deform the striking protrusion until slipping and resetting, so as to generate a prompt sound by accumulating and releasing elastic potential energy.

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