Hair straightener

Abstract

In a hair straightener including an elongate straightening arm (A) having a heating plate (H), the present invention provides a pivot mechanism (2) for pivotally supporting the heating plate (H) about a pivot axis (PI) in the longitudinal direction of the elongate straightening arm (A). Preferably, when the first and second straightening arms are in a relative position arranged for clamping hair, the pivot axis (PI) is at the heating surface of the heating plate (H), or between a first heating plate of the first straightening arm and a second heating plate of the second straightening arm. Advantageously, a biasing mechanism (4) (such as an elastic mechanism, such as a certain spring) biases the heating plate (H) to a neutral position.

Description

Technical Field

[0001] The present invention relates to a hair straightener. Background Art

[0002] US2015136169 discloses a hair styling device that includes a first arm and a second arm, which respectively include a heatable plate and an arm member. The first arm and the second arm are movable between a closed position where the heatable plates of the first arm and the second arm are adjacent to each other and an open position where the heatable plates of each arm are spaced apart. The heatable plate of at least one arm is coupled to the corresponding arm member about a pivot axis that is arranged to allow the heatable plate to move relative to the corresponding arm member about an axis transverse to the length of the corresponding arm member such that the plate pivots.

[0003] JP2014217748 discloses a hair curling iron that can include a heating member that sandwiches hair between a pair of arms that can be opened and closed. A first heating surface is formed in a skewed shape of 30° to 80° with respect to the opening / closing direction of the arms. A holding member holds the heating member in an inclined position.

[0004] US 2010 / 083978 A1 discloses a hair styling device having a substantially cylindrical heating member, and at least one heatable styling member is provided on the heating member to heat hair. Guide means are arranged around the styling member. The heatable styling member and the guide means can rotate relative to each other. Summary of the Invention

[0005] An object of the present invention is in particular to provide an improved hair straightener. The present invention is defined by the independent claims. Advantageous embodiments are defined in the dependent claims.

[0006] One aspect of the present invention provides a hair straightener including an elongate straightener arm having a heating plate, wherein a pivot mechanism pivotally supports the heating plate about a pivot axis in a longitudinal direction of the elongate straightener arm. Preferably, when the first straightener arm and the second straightener arm are in a relative position arranged for clamping hair, the pivot axis is at the heating surface of the heating plate or between a first heating plate of the first straightener arm and a second heating plate of the second straightener arm. Advantageously, a biasing mechanism (such as an elastic mechanism, such as a certain spring) biases the heating plate to a neutral position.

[0007] The various embodiments of the present invention are based on the following considerations. Hair straighteners are used to straighten hair. They mainly consist of two arms, each having a heating plate at each end. Most of these plates are suspended via rubber to allow them to flex when hair is between them. This flexing helps to prevent pulling force and better heat distribution, and slightly reduces the resistance / stick-slip. However, the system is force-balanced via rubber, so the plates cannot optimally follow the hair and may result in inefficiency. Advantageous embodiments provide a virtual pivot point at the hair level and a freely adjustable plate that automatically follows the hair shape / curve and adapts to the force. This will result in better heat transfer and better and more controllable sliding.

[0008] With reference to the embodiments described below, these and other aspects of the present invention will become apparent and be elucidated. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A and Figure 1B illustrates an embodiment of a hair straightener according to the present invention.

[0010] Figure 2 illustrates a detailed view of a pivot mechanism according to an embodiment of the present invention;

[0011] Figures 3A to 3C illustrates Figure 2 the movement of the pivot mechanism shown;

[0012] Figures 4A to 4C illustrates the movement of a pivot mechanism according to another embodiment of the present invention;

[0013] Figure 5A illustrates a detailed view of a pivot mechanism according to another embodiment of the present invention;

[0014] Figure 5B illustrates Figure 5A a side view of the pivot mechanism shown;

[0015] Figures 6A to 6C illustrates the movement of a pivot mechanism according to yet another embodiment of the present invention;

[0016] Figure 7 illustrates a pivot mechanism according to an embodiment of the present invention; and

[0017] Figure 8 illustrates a pivot mechanism according to another embodiment of the present invention.

[0018] In the drawings, the same or similar reference numerals are used to indicate the same or similar elements. DETAILED DESCRIPTION

[0019] Figure 1A 、Figure 1B shows a cross-section of a pair of elongated hair straightener arms A. The longitudinal direction of the straightener arm A is perpendicular to Figure 1A and Figure 1B the two-dimensional cross-section of. In Figure 1A and Figure 1B embodiments, in the hair straightener arm A, the pivot mechanism is formed by rolling members R1, R2. The pivot mechanism is between the body of the arm A and the heating plate H. The rolling member R1 allows the heating plate H mounted thereon to be tilted by the rolling member R2. FIG. 1 shows the heating plate H in the neutral position, while Figure 2 shows the heating plate H in the tilted position. By allowing the heating plate H to tilt, they can follow the hair so that the hair is not subjected to undesired bending.

[0020] Figure 2 illustrates a detailed view of another pivot mechanism 2 in a hair straightener according to the present invention. The pivot mechanism 2 defines a virtual first pivot axis PI that is parallel to the surface to which the heating plate H is attached. During operation, in response to the movement of the pivot mechanism 2, the virtual pivot axis PI automatically moves along a defined path. In Figure 5A , the movement of the pivot mechanism 2 is schematically illustrated by an arrow 6. In various embodiments of the present disclosure, the pivot mechanism 2 includes a top 21 coupled to the heating plate H (the heating plate H is not shown in Figure 2 for clarity) and a support portion 22 coupled to the base 1. The top 21 and the support portion 22 are movable relative to each other such that the heating plate H is pivotally supported by the pivot mechanism 2 during operation.

[0021] As Figure 2 further illustrated, the first pivot axis PI of the top 21 defined by the pivot mechanism 2 is parallel to the surface 211 defined by the top 21. During operation, the first pivot axis PI is substantially located in the surface 211 of the top 21 or at a defined height h above the surface 211 on the side opposite to the base 1.

[0022] As used herein, the virtual pivot axis can be regarded as the instantaneous rotation axis of the mounted heating plate H defined by the pivot mechanism 2. During operation, the heating plate H can pivot relative to the body 1 of the hair appliance. When in use, the virtual pivot axis PI can be located on the hair surface or in the hair. Therefore, the pivot response ability of the pivot mechanism 2 when being guided through the hair for styling can be correspondingly adjusted. In this way, the hair following ability of the heating plate H can be improved.

[0023] Figures 3A to 3C illustrates Figure 2Movement of the pivot mechanism 2 as shown. As shown, the pivot mechanism 2 can be switched between a first position and a second position. In the first position, the surface of the top 21 forms a first angle relative to the surface of the base 1. In the second position, the surface of the top 21 forms a second angle relative to the surface of the base 1, and this second angle is different from the first angle.

[0024] In Figures 3A to 3C the example shown, the first position can be a neutral position ( Figure 3B ), and the second position can be a swivel position ( Figure 3A and Figure 3C ). When the pivot mechanism 2 is in the neutral position, the angle between the surface of the top 21 and the surface of the base is zero, that is, the two surfaces are parallel to each other. When the pivot mechanism 2 is in the swivel position, the surface of the top and the surface of the base form a non - zero angle. In other words, during the pivoting movement, the heating plate H can continuously move back and forth within a given angle range. Again, for clarity, the heating plate H is only shown in Figure 3B .

[0025] This can be beneficial because the hair - following ability of the heating plate H can be further improved in this way. When moving above the hair, the heating plate H can be regarded as a lever associated with a corresponding pivot point defined by the virtual pivot axis PI. In Figures 3A to 3C the case illustrated, this may even be further beneficial, where the virtual pivot PI is arranged in the central or intermediate part of the heating plate H.

[0026] Still referring to Figures 3A to 3C , in some embodiments, the hair appliance may further include an elastic member 4 coupled to the pivot mechanism 2. The elastic member 4 is configured to provide resistance to the pivot mechanism 2 when the pivot mechanism 2 is switched from the first position to the second position. On the other hand, the elastic member 4 is also configured to return the pivot mechanism 2 from the second position to the first position. By adding the elastic member 4 to the pivot mechanism 2, a smoother and more balanced operation of the pivot mechanism 2 can be ensured.

[0027] For example, in some embodiments, the elastic member 4 can be a spring with a constant spring constant or a spring with a constant torque. When the pivot mechanism 2 rotates further away from the neutral position, adding a spring with a constant spring constant will result in a greater force. On the other hand, a constant - torque spring will keep the force constant.

[0028] In Figures 3A to 3C the illustrated exemplary embodiment, a spring with a constant spring constant is employed. In this example, one end of the spring is coupled to the top 21 of the pivot mechanism 2, and the other end of the spring is coupled to the base 1. It should be understood that by lengthening or shortening the spring to change its pre - tension force, the force exerted by the spring can be changed manually or electrically.

[0029] The resilient element 4 can be defined or selected such that when the heating plate H is guided along the hair, for example, at a substantially curved neck region, the return force is small enough to be easily overcome during the operation of the styling operation. Thus, after the external load or force is just released, the heating plate H can be substantially self-aligned relative to the hair surface and, in addition, can self-return.

[0030] Still referring Figures 3A to 3C , in some embodiments, the pivot mechanism 2 is arranged as a three-bar linkage mechanism having a trapezoidal shape. As shown, the three-bar linkage pivot mechanism includes a first bar 23 and a second bar 24 arranged opposite to the first bar 23, and both are configured as support portions 22 of the pivot mechanism 2. Further, the three-bar linkage pivot mechanism further includes a top bar (also referred to as a "connecting bar") that is coupled to the first bar 23 and the second bar 24 and is configured as the top 21 of the pivot mechanism 2.

[0031] As Figures 3A to 3C Further illustrated, the first bar 23 includes a first base pivot 231 coupled to the base 1 and a first top pivot 232 coupled to the top bar. Further, the second bar 24 includes a second base pivot 241 coupled to the base 1 and a second top pivot 242 coupled to the top bar. The first base pivot 231 and the second base pivot 241 are arranged at the base 1 and are separated by a predefined distance d1.

[0032] Since it is generally desirable to reduce the size and mass of the hair appliance, especially the heating plate H, there are practical design limitations for positioning the pivot of the heating plate H. This is because the installation space for the traditional single-axis linkage unit or circular joint, knee joint (usually the axis or joint is located on the side of the heating plate H opposite to the hair) used to implement the heating plate H is limited. Moreover, the possible range of the area where the pivot axis can be placed may be limited. Therefore, the installation of such a traditional heating plate H can be considered to adversely affect the hair-following ability of the heating plate H because a rather poor swiveling behavior may occur.

[0033] It has been observed that the three-bar linkage mechanism can be designed in a suitable manner such that a virtual pivot axis PI can be defined, which can also be regarded as a moving (or floating) virtual pivot. As Figures 3A to 3C Illustrated, during the pivoting movement of the heating plate H back and forth, the three-bar linkage mechanism can be designed such that the virtual pivot is (virtually) arranged. Given the available installation space, the virtual pivot axis PI is located at a defined distance from the top 21, which cannot be achieved by the traditional single-pivot coupling mechanism. In some cases, the resulting virtual pivot can even be arranged at a part of the hair appliance that is substantially obstructed by other components, such as in the middle of the heating plate H.

[0034] In Figures 3A to 3C some of the illustrated embodiments, the length of the base 1 defined by the distance d1 between the first base pivot 231 and the second base pivot 241 is greater than the length of the top 21 defined by the distance d2 between the first top pivot 232 and the second top pivot 242. In this way, the virtual pivot axis PI can be shifted in the first position and in the upward direction at the level of the top 21, or in other words, shifted into the hair.

[0035] In some embodiments, at least one of the first base pivot 231, the second base pivot 241, the first top pivot 232, and the second top pivot 242 is configured as a living hinge, in particular a membrane hinge. Figures 4A to 4C An embodiment of the pivot mechanism 2 of the present disclosure is illustrated. In this example, all of the first base pivot 231, the second base pivot 241, the first top pivot 232, and the second top pivot 242 are configured as membrane hinges.

[0036] A membrane hinge or a thin film hinge can be manufactured, for example, via an injection molding process. Thus, at least one of the pivot and the corresponding adjacent components connected by the pivot can be produced integrally from substantially the same material. This arrangement can also ensure that there is substantially no (mechanical) play in the pivot. A mechanical joint consisting of separate components is typically designed in a clearance fit manner, which includes a defined play to allow smooth pivoting movement. Moreover, a membrane hinge can also have the advantage that any (internal) contamination of the joint can be prevented. According to another embodiment, at least the first rod, the second rod, and the top rod of the three-bar linkage mechanism and their corresponding base pivots and top pivots are integrally formed as a single piece.

[0037] Figures 5A to 5B Another embodiment of the present disclosure is illustrated. In this example, the pivot mechanism 2 further includes a second pivot axis P2 of the top 21. The second pivot axis P2 is arranged substantially perpendicular to the first pivot axis PI. In this way, in addition to the virtual first axis PI that enables the heating plate H to pivotally move with two-dimensional (2D) degrees of freedom (DoF) (as illustrated by the arrow 6), an additional actual axis P2 in the direction perpendicular to the virtual first axis PI can be provided to enable pivoting movement in the third dimension (as illustrated by the arrow 7), thereby achieving three-dimensional (3D) DoF. In other words, when viewed along the second pivot axis P2, the second pivot can be regarded as a rocking point ( Figure 5B ).

[0038] Figures 6A to 6CAnother embodiment of the pivot mechanism 2 of the present disclosure is illustrated. In this example, the pivot mechanism 2 is arranged as a bearing mechanism, which includes a rotor 21 and an optional rolling member 22 (such as a roller or a wheel), and the rolling member 22 is arranged between the rotor 21 and the base 1 to pivotally support the rotor 21. In this embodiment, the rotor is configured as a top 21, and the rolling member is configured as a support 22.

[0039] This type of pivot mechanism 2 can be beneficial because the pivot mechanism 2 can have a further reduced size since the rolling member generally only consumes very little space, which will further improve the compactness of the hair appliance. However, instead of using the rolling member 22, the pivot mechanism 2 can be implemented as a sliding bearing.

[0040] Figure 7 An embodiment of the pivot mechanism 2 shown in FIG. 6 is schematically illustrated. In this example, the top 21 (i.e., the rotor) is configured as a partial cylinder, and the partial cylinder includes a rectangular cross-section that defines the surface 211 of the top 21. Here, the roller 22 shown in FIG. 6 is omitted.

[0041] In this case, due to the geometry of the partial cylinder, the virtual axis PI is above or within the surface 211 of the top 21, and its position remains unchanged (or does not float). As Figure 7 The example of shows that the partial cylinder has a semi-circular end face, which corresponds to an arc of 180°. In this case, as Figure 7 shown, the virtual axis PI is located in the surface 211 of the top 21. In other words, the virtual axis PI can also be regarded as the central axis of the cylinder from which the partial cylinder is obtained. In another embodiment, when the partial cylinder has a smaller semi-circular end face (i.e., corresponding to an arc of less than 180°), the virtual axis is above the surface of the top.

[0042] Figure 8 Another embodiment of the pivot mechanism 2 shown in FIG. 6 is illustrated. In this example, the top 21 (i.e., the rotor) is configured as a partial sphere, and the partial sphere includes a circular cross-section that defines the surface 211 of the top 21. Compared with Figure 7 The partial cylindrical rotor shown, the partial spherical rotor can provide 3D pivotal movement, which further improves the flexibility of hair following during the grooming operation.

[0043] In some embodiments, the hair appliance may further include a sensor configured to detect the angle between the top 21 and the hair during operation. Therefore, the pivot mechanism 2 can be configured to pivot, for example, under the control of an actuator in response to detecting that the angle exceeds a threshold angle to "actively" reduce the angle.

[0044] This can be beneficial as it provides a forward-looking pivoting mechanism. In other words, when the actual angle deviates from the optimal angle by only a small value, the pivoting mechanism 2 can start pivoting at an early stage. In this way, it provides the pivoting mechanism in a more accurate manner. Moreover, this forward-looking pivoting mechanism can also improve comfort as the pivoting mechanism 2 will start pivoting earlier rather than waiting until the top 21 receives a certain amount of external force resulting from the interaction between the heating plate H and the hair.

[0045] It should be noted that the above embodiments illustrate rather than limit the invention, and those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising a plurality of different elements. In a device claim enumerating several components, several of these components may be implemented by the same item of hardware. The measures recited in mutually different dependent claims may be used advantageously in combination.

Claims

1. A hair straightener, comprising: An elongate first straightener arm (A) and a pivot mechanism (2), the first straightener arm (A) having a first heating plate (H), the pivot mechanism (2) being configured to pivotally support the first heating plate (H) about a virtual pivot axis (P1) in the longitudinal direction of the first straightener arm (A), A second straightener arm having a second heating plate, Wherein the first heating plate and the second heating plate are freely adjustable such that they automatically follow the shape / curve of the hair and adapt to the force, and Wherein when the first straightener arm and the second straightener arm are in a relative position arranged for clamping the hair, the virtual pivot axis (P1) is at the heating surface of the first heating plate (H), or between the first heating plate of the first straightener arm and the second heating plate of the second straightener arm, and the virtual pivot axis automatically moves along a defined path.

2. The hair straightener according to claim 1, further comprising a biasing mechanism for biasing the first heating plate (H) to a neutral position.

3. The hair straightener according to claim 2, wherein the biasing mechanism includes an elastic member (4) coupled to the pivot mechanism (2) and configured to provide resistance to the pivot mechanism (2) when the pivot mechanism (2) switches from the neutral position to an angled position and to return the pivot mechanism (2) from the angled position to the neutral position.

4. The hair straightener according to any one of claims 1-3, wherein the pivot mechanism (2) is arranged as a three-bar linkage mechanism, the three-bar linkage mechanism comprising: A support portion (22) between the body of the first straightener arm (A) and the first heating plate (H), the support portion (22) including a first rod (23) and a second rod (24) arranged opposite to the first rod (23); and A top portion (21) coupled to the first rod (23) and the second rod (24), wherein the first rod (23) includes a first base pivot (231) and a first top pivot (232), the first base pivot (231) being coupled to the body of the first straightener arm (A), the first top pivot (232) being coupled to the top portion (21), and the second rod (24) includes a second base pivot (241) and a second top pivot (242), the second base pivot (241) being coupled to the body of the first straightener arm (A), the second top pivot (242) being coupled to the top portion (21), wherein the first base pivot (231) and the second base pivot (241) are separated by a base distance that exceeds the top distance between the first top pivot (232) and the second top pivot (242).

5. The hair straightener according to claim 1, wherein the pivot mechanism (2) is arranged as a bearing mechanism, the bearing mechanism including: A rotor that supports the first heating plate (H); and a member that is disposed between the rotor and the body of the first straightening arm (A) to pivotally support the rotor.

6. The hair straightener according to claim 5, wherein the rotor is configured as a partial cylinder or sphere having a top that supports the first heating plate (H).

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