Straightener with adjustable closing pressure for jaws

Abstract

The present invention discloses a straightener comprising a straightener that comprises an upper jaw and a lower jaw which are hinged and movable between an open position and a closed position, and an adjustment device for adjusting the closing force of the jaws, wherein the adjustment device comprises: - a spring; - an adjustable preloading means for preloading the spring; - a compression means for compressing the spring when closing the jaws; characterised in that the adjustment device comprises an adjustment wheel for adjusting the preloading force exerted by the preloading means on the spring, wherein the adjustment wheel is accessible to the user, which enables the user, during use, to manually adjust the preloading force exerted by the preloading means on the spring in order to vary the pressure to be applied to the jaws by means of the compression means, thereby moving them from the open position to the closed position.

Description

STRAIGHTENER WITH ADJUSTABLE JAW CLOSING PRESSURE Subject of the invention

[0001] The present invention relates to the field of hairdressing devices, and in particular to that of hair straighteners, comprising a device for adjusting the pressure that the user must apply to the jaws of the straightener to close the device. State of the art

[0002] Hair straighteners, or straighteners, are well known to those skilled in the art. Most hair styling and straightening devices rely on the principle of passing strands of hair between two jaws containing heated plates. The closing pressure to be applied to the jaws is always the same. However, users may have a preference for more or less pressure, especially if they are professionals who use this type of device frequently and must close and open the clamps repeatedly.

[0003] Document KR102238285 B1 discloses a hair straightener comprising an electrical control means for controlling the pressure applied to the hair by the heating plates. The user selects a pressure to be applied and the controller allows the pressure to be adjusted and maintained at the same level throughout the styling process.

[0004] Document KR101311806 B1 discloses a hair straightener comprising means for adjusting the intensity of the gripping force that must be manually applied to press the hair between the heating plates of the hair straightener. To achieve this, a spring is provided between the two jaws of the straightener, and a small winch is placed inside the spring. The winch cable can be wound or unwound, thanks to a motor provided for this purpose. The user can operate the motor via a switch placed on the handle of the straightener, in order to wind or unwind the winch cable to increase or decrease the preload of the spring. In this way, the intensity of the gripping force is variable and adjustable by the user. Aims of the invention

[0005] The present invention aims to overcome the drawbacks of the state of the art, and in particular to provide a straightener with a means for adjusting the pressure to be applied to the jaws when closing them, easy to implement.

[0006] Another aim of the invention is to provide a solution that avoids the use of electronic or electrical means for adjusting the closing pressure of the jaws. The aim is to provide a device that is inexpensive, easy to implement and simple to maintain. Since a hairdressing appliance is a mass-market product, its price must remain affordable and the use of a motor or any electronics for adjusting the closing pressure does not meet this criterion and makes the product more expensive.

[0007] Another aim of the invention is to provide a solution that is both compact and lightweight so as not to weigh down the hair straightener. It is essential that the device is easy to handle and allows the user good flexibility during styling movements. Summary of the invention

[0008] The present invention discloses a straightener comprising an upper jaw and a lower jaw articulated and movable between an open and closed position, and a device for adjusting the closing pressure of the jaws comprising: - a spring; - an adjustable means of pre-stressing the spring; - a means for compressing the spring when the jaws are closed; said adjustment device comprises a wheel for adjusting the pre-stressing force exerted by the pre-stressing means on the spring, said adjustment wheel being accessible to the user who can, in use, manually adjust the pre-stressing force exerted by the pre-stressing means on the spring in order to vary the pressure to be applied to the jaws using the compression means to move them from the open position to the closed position.

[0009] According to particular embodiments, the invention comprises one or more of the following characteristics: the closing pressure, thanks to the adjustment device, varies at least from single to double, preferably at least from single to triple, even more preferably at least from single to quadruple; the minimum pressure for closing the jaws is between 1.5 and 2.5 N and the maximum pressure for closing the jaws is between 7.5 and 12.5 N; the spring prestressing means comprises a threaded rod passing through the spring, the first end of the threaded rod being connected to the wheel, and the second end being provided with a threaded nut, the rotation of the wheel making it possible to rotate the threaded rod, causing the translation of the nut to put the spring into compression or vice versa; the spring compression means comprises a cylinder for compressing the spring by translation; the spring compression means comprises a pivoting tab making it possible to transmit the rotational force of the upper jaw when the jaws are closed to the spring compression cylinder; the threaded rod has its axis parallel to the longitudinal axis of the straightener; the compression / decompression axis of the spring is parallel to the longitudinal axis of the straightener;the pivoting tab comprises at a first end a first axis connected to the upper jaw, and at a second end a second axis connected to the compression cylinder of the spring, said tab making it possible to transmit the rotational force of the upper jaw to the compression cylinder, said compression cylinder compressing the spring by translation when the jaws close; the compression cylinder has the same longitudinal axis as the spring and surrounds the threaded rod so as to be in contact with the spring in order to be able to compress it when the jaws close; the spring is housed between the threaded nut of the prestressing means and the compression cylinder of the compression means; the device for adjusting the closing pressure is housed in the proximal part of the lower jaw.; Brief description of the figures

[0010] Figure 1 represents a three-dimensional view of an example of a straightener according to the invention, the jaws being closed.

[0011] Figure 2 shows a three-dimensional side view of the straightener of Figure 1 with the jaws closed.

[0012] Figure 3 shows a longitudinal section of the straightener of Figure 1, with the jaws open.

[0013] Figure 4 represents an enlargement of Figure 3 in order to detail the pressure adjustment device according to the invention, the jaws being open.

[0014] Figure 5 represents an enlargement of Figure 3 in order to detail the pressure adjustment device according to the invention, the jaws being closed. List of reference symbols 1: straightener 2: upper jaw 3: lower jaw 4: hinge for articulation of the two jaws between them 5: jaw closing pressure adjustment device 6: spring preload adjustment wheel 7: adjustment device spring 8: adjustable spring preloading means 81: spring preload threaded rod 82: threaded nut for spring preloading 9: spring compression means 91: swivel tab 92: spring compression cylinder by translation 93: first axis of the pivoting tab 94: second axis of the pivoting tab 10: heating plate of each jaw 11: Power cord Detailed description of the invention

[0015] An example of a straightener 1 according to the invention is illustrated in Figure 1. This comprises an upper jaw 2 and a lower jaw 3 hinged between an open position and a closed position for clamping strands of hair. The articulation may be around a hinge 4 incorporating an element (e.g. a spring - not shown) to exert a force on the jaws to keep them in the open position. In the rest position, the jaws are open and no external force is applied by the user (and in the particular case of the spring, the hinge spring is relaxed). When the jaws are in the working position, they are closed and the user must apply an external force to them in order to move them from the open position to the closed position. The working position therefore corresponds to the position used to straighten the hair between the clips.

[0016] The two jaws comprise plates 10, preferably heated, on the internal side of the jaws, that is to say in such a way that the two plates allow the lock of hair to be pressed into the closed position. These plates can be smooth, as shown in the figures, or include reliefs in order to give particular effects to the hair (waving, backcombing, etc.). The plates are preferably heated by electrical resistors.

[0017] The straightener of the present invention comprises a device 5 for adjusting the closing pressure of the jaws, so that the user can vary as desired the pressure that he must apply to the jaws to move them from their open position, where the jaws are distant from each other, to their closed position, where the jaws pinch the hair to style it. This device allows the closing pressure to be manually adjusted using an adjustment wheel 6 which is accessible to the user. Preferably, this wheel is located in the proximal part of the straightener, as illustrated in the figures (namely, on the side of the power cord 11 of the straightener if it is not battery-powered). The adjustment device is a purely mechanical device which does not require any energy input other than the user's strength.

[0018] More specifically, the adjustment device comprises a spring 7 which will be compressed when closing the jaws, by a means of compressing the spring 9. If the user wants to modify the pressure to be exerted on the jaws when using the straightener, he will have to turn the adjustment wheel, which will have the role of pre-stressing the spring of the adjustment device more or less. So that the wheel, and therefore the user, can act on the degree of pre-stressing of the spring, the adjustment device includes a pre-stressing means 8. The more the spring is pre-stressed, the higher the pressure to close the jaws will be because the user will have to counter the pre-stressing force of the spring so that the jaws can close.

[0019] The spring compression means 9 may comprise, for example, a spring compression cylinder 91, in contact with the spring, and a pivoting tab 92, as illustrated in FIGS. 4 and 5. The pivoting tab comprises at one of its ends a first rotation axis 93 fixed to the upper jaw, and at the other of its ends a second rotation axis 94 connected to the compression cylinder. When the user closes the jaws against each other the other, the upper jaw rotates thanks to the hinge which articulates the two jaws. The tongue will transmit this rotation of the jaw to the compression cylinder. Thanks to the connections of the tongue via its two rotation axes 93 and 94, the rotational movement of the jaw will be transformed into a translational movement of the cylinder. This translational movement of the cylinder will compress the spring of the adjustment device.

[0020] As explained previously, if the user wants to modify the pressure to be exerted on the jaws when using the straightener, he will have to turn the adjustment wheel, which will have the role of pre-stressing the spring of the adjustment device more or less. The tab and the compression cylinder will have to compress the spring (more or less pre-stressed) so that the jaws can close. The pre-stressing means 8 of the spring can comprise for example a threaded rod 81 and a threaded nut 82, as shown in Figures 4 and 5. The threaded rod passes inside the spring, and passes axially through it. On one side, its first end is connected to the adjustment wheel. On the other side, its second end is provided with the threaded nut. In this way, the rotation of the wheel causes the rotation of the threaded rod, which causes the translation of the nut.

[0021] As illustrated in Figure 4, the spring 7 is housed between the threaded nut 82 and the compression cylinder 91. The compression cylinder is located around the threaded rod and is in contact with the spring so that it can be compressed when the jaws are closed. When the user turns the adjustment wheel, the nut will move and then compress the spring by compressing it against the cylinder (or vice versa).

[0022] Preferably, the threaded rod has its longitudinal axis parallel to the longitudinal axis of the straightener. Similarly, the compression and depression axis of the spring is parallel to the longitudinal axis of the straightener. The compression cylinder has the same longitudinal axis as the spring.

[0023] Preferably, the minimum pressure is between 1.5 and 2.5N and the maximum pressure to close the jaws is between 7.5 and 12.5N.

[0024] The closing pressure, thanks to the adjustment device, varies at least from single to double, preferably from single to triple, still preferably at least from single to quadruple. In a most advantageous version, the closing pressure can vary at least from single to eightfold thanks to the adjustment device.

Claims

CLAIMS 1. Straightener (1) comprising an upper jaw (2) and a lower jaw (3) articulated and movable between an opening position called rest and a closing position called working, the upper (2) and lower (3) jaws being in the opening position when they are at rest and no external force is applied to them, the two jaws (2, 3) comprising plates (10) on their internal side so that the two plates (10) make it possible to press the hair in the closed position, the straightener comprising a device (5) for adjusting the closing pressure of the jaws comprising: - a spring (7); - an adjustable pre-stressing means (8) for the spring; - a means (9) for compressing the spring when the jaws are closed; characterized in that said adjustment device (5) comprises an adjustment wheel (6) of the prestressing force exerted by the prestressing means (8) on the spring (7), said adjustment wheel (6) being accessible to the user who can, in use, manually adjust the pre-stressing force exerted by the pre-stressing means (8) on the spring (7) in order to vary the pressure to be applied to the jaws (2, 3) using the compression means (9) to move them from the rest position to the working position.

2. Straightener (1) according to claim 1, characterized in that the closing pressure, thanks to the adjustment device (5), varies at least from single to double, preferably at least from single to triple, even more preferably at least from single to quadruple.

3. Straightener (1) according to any one of the preceding claims, characterized in that the minimum pressure for closing the jaws (2, 3) is between 1.5 and 2.5 N and the maximum pressure for closing the jaws (2, 3) is between 7.5 and 12.5 N.

4. Straightener (1) according to any one of the preceding claims, characterized in that the prestressing means (8) of the spring comprises a threaded rod (81) passing through the spring (7), the first end of the threaded rod (81) being connected to the wheel (6), and the second end being provided with a threaded nut (82), the rotation of the wheel (6) making it possible to rotate the threaded rod (81), causing the translation of the nut (82) to put the spring (7) in compression or vice versa.

5. Straightener (1) according to any one of the preceding claims, characterized in that the spring compression means (9) comprises a cylinder for compressing the spring by translation (91).

6. Straightener (1) according to any one of the preceding claims, characterized in that the compression means (9) of the spring comprises a pivoting tab (92) making it possible to transmit the rotational force of the upper jaw (2) when the jaws (2, 3) are closed to the compression cylinder of the spring (91).

7. Straightener according to any one of the preceding claims, characterized in that the threaded rod (81) has its axis parallel to the longitudinal axis of the straightener (1).

8. Straightener according to any one of the preceding claims, characterized in that the compression / decompression axis of the spring (7) is parallel to the longitudinal axis of the straightener (1).

9. Straightener according to claims 5 and 6, characterized in that the pivoting tongue (92) comprises at a first end a first axis (93) connected to the upper jaw (2), and at a second end a second axis (94) connected to the compression cylinder (91) of the spring, said tongue making it possible to transmit the rotational force of the upper jaw (2) to the compression cylinder (91), said compression cylinder (91) compressing the spring (7) by translation when the jaws close.

10. Straightener according to claims 4 and 5, characterized in that the compression cylinder (91) has the same longitudinal axis as the spring (7) and surrounds the threaded rod (81) so as to be in contact with the spring (7) to be able to compress it when closing the jaws (2, 3).

11. Straightener according to claims 4 and 5, characterized in that the spring (7) is housed between the threaded nut (81) of the prestressing means (8) and the compression cylinder (91) of the compression means.

12. Straightener according to any one of the preceding claims, characterized in that the closing pressure adjustment device (5) is housed in the proximal part of the lower jaw (3).

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