Piston-damped tapping cosmetic device

The present invention relates to a device for applying a cosmetic product to a body surface of a user, and to the associated method. More specifically, the invention relates to a device comprising an applicator intended to come into contact with the body surface of the user while effecting back-and-forth movements.

The product applied by the device is in particular a makeup product, advantageously intended to be applied to the skin.

In a variant, the cosmetic product is a care product, in particular a face cream or body cream formula, a shampoo, a hair mask, a makeup removing oil, a treatment oil, a cleansing cream, an exfoliant, a mask or a sunscreen.

More generally, the expression "cosmetic product" is understood to mean any product as defined in Regulation (EC) No 1223/2009 of the European Parliament and Council of 30 November 2009 relating to cosmetic products.

The device according to the invention is in particular intended to apply the cosmetic product to the body surface of the user. It can also be intended to cleanse this body surface with the aid of the cosmetic product.

In the former case, it is common to use passive application devices that comprise an applicator member on which the cosmetic product is disposed.

During the application of the product, the user manually moves the applicator member with respect to the body surface.

In order to apply makeup, the cosmetic product can be disposed on an applicator member, and the user taps on his/her skin with the aid of the applicator member in order to apply the product so as to carry out a touch up or care treatment.

In the prior art, there are devices that are capable of tapping on the body surface of the user. From a mechanical point of view, this tapping is generally achieved with the aid of a rotary cam that is intended to convert a rotary movement of a motor into a vibratory movement of an applicator along a tapping axis.

The document KR2010-0060730 describes a device of the abovementioned type, in which the cam has a surface with an elongate and rounded shape and is in permanent contact with the applicator. However, if the applicator becomes blocked, this solution sometimes causes the motor to break. This can happen for example when the user stresses the applicator by pressing it.

Other types of device that are suitable for producing oscillations or vibrations on the body surface of the user are also known.

The patent KR20120078856 describes a motorized toothbrush comprising a body, a motor housed in the body, a stem and an applicator fixed to the end of the stem. The motor is connected to a gear system that brings about a rotational movement of the applicator.

The document US5033150 describes a motorized toothbrush comprising an applicator and a stem inserted into a case. The case also comprises a rotating motor coupled to the stem. The rotational movement of the motor brings about an oscillating movement of the applicator.

The document WO2010095830 describes an electric mascara in which the mascara brush is made to move from left to right. The motor is connected to a gear system. One of the wheels has a protuberance which is inserted into a hole in the mascara brush, bringing about the movement thereof from left to right.

However, these devices are not satisfactory from a technical point of view. Specifically, the applicator is made to move in a rotational or oscillating movement and not in a back-and-forth movement. The application of the product will not be homogeneous. Moreover, the movement does not reproduce the desired "whiplash" gestures, that is to say an extremely quick movement which allows a "whiplash" type application of product.

The aim of the invention is to provide a cosmetic tool with a back-and-forth movement on the body surface of the user, which:

- is rapid,

- imitates the extremely quick gestures that are characteristic of "whiplash",

- provides a sufficiently large amplitude of movement of the applicator,

- results in damping of the applicator that is sufficient to avoid the body surface being struck too violently.

Also desired is a tool which, preferably, is quieter than the already existing tools. To this end, the invention proposes a device for applying a cosmetic product by tapping, comprising:

- grip,

an applicator that effects a back-and- forth movement,

- a motor,

a cam mechanism comprising a piston damper.

The piston damper damps the movement of the applicator.

Thus, the applicator is made to move in a translational movement. The piston damper ensures that the applicator comes into gentle contact with the body surface. The intensity of the impact on the body surface is reduced, attenuated. Contact is made with the body surface in a smooth manner.

A further subject of the invention is a method for applying a cosmetic product, comprising the use of a device according to the invention.

Preferably, the method comprises the application of a care, makeup or cleansing composition.

MAIN DEFINITIONS

The tapping of the applicator on the body surface is produced by a back-and- forth movement of the applicator along a tapping axis X.

The "back-and-forth movement" is an oscillating movement of the applicator along the tapping axis X between two end positions:

- a rest position, in which the applicator is in its retracted position, that is to say its position furthest away from the body surface, and

- a position of maximum action, in which the applicator exerts a maximum pressure on the body surface.

In general, the motor sets an output shaft of the motor into rotation about a longitudinal axis Y perpendicular to the tapping axis X. The output shaft of the motor subsequently drives a cam mechanism.

A "shaft" is a mechanical member that transmits power in the form of torque and of a rotational movement.

A "cam mechanism" is a mechanism comprising a cam and a follower. A cam is a mechanical member for controlling the movement of a part. It is a part that rolls (or slides) on another part. The cam makes it possible to generate reciprocating movements.

The most widespread cam is constituted of a cylinder of variable radius that is driven in rotation by a shaft. The part in contact with the profile of the cam, the follower, is then set in movement.

The contact between the profile of the cam and the follower is continuous so as to avoid impacts, vibrations and noise. The follower is generally kept in contact with the profile of the cam by a spring.

The movement is transmitted by direct contact or by indirect contact by way of a roller. The direct contact brings about resistive torque on the cam on account of friction, this causing a loss of energy dissipated in the form of heat in the two parts in contact.

The use of a roller makes it possible to increase the efficiency of this transmission system by reducing friction.

According to the invention, a "piston damper" is a damper for the movement of the applicator that acts by way of a piston mechanism. A "damper" is a system intended to limit, or even eliminate, the oscillations of an object. During oscillations, there is an alternation between kinetic energy and potential energy. A damper dissipates a part of the kinetic energy, most frequently as heat. The damper is a device added to the cam mechanism. It damps and slows down the travel of the follower. In general, the damper is a component of the follower.

A "piston damper" is a damper comprising a piston.

A "piston" comprises a rod formed by a rigid part having a generally circular section. This rod slides in a cylinder of complementary shape. The movement of the rod brings about a variation in the volume of a chamber. The movement of the rod brings about or is brought about by pressure inside the chamber. A piston converts pressure into work, or vice versa.

An "applicator" is a part comprising a surface intended to come into contact with the body surface. The device according to the invention may include one or more of the following characteristics, taken separately or in any technically possible combination(s). These characteristics are preferred embodiments. PREFERRED EMBODIMENTS

- The piston damper comprises a spring.

The spring allows a gradual decrease in the oscillating movement under the effect of its resistance.

If the applicator is immobilized in an end position, the spring exerts a disengaging function, allowing the motor to continue turning without breaking the mechanical parts.

- The piston damper is housed in a sleeve.

The sleeve serves as a means for guiding the piston rod. It also keeps the cylinder in a fixed position. The device is more precise.

- The frequency of the back-and- forth movement is between 5 Hertz and 50

Hertz, preferably between 15 Hertz and 25 Hertz.

The "frequency" is the number of times that a complete back-and-forth movement recurs per unit time.

This frequency is close to the tapping frequency naturally carried out by a person.

- The amplitude of movement of the applicator is between 2 mm and 20 mm, preferably between 7 mm and 13 mm.

The "amplitude" is the difference between the end positions of the applicator.

The body surface can relax between two tappings.

- The average acceleration of the applicator is between 3 m/s ² and 50 m/s ² , preferably between 5 m/s ² and 20 m/s ² , preferably around 7 m/s ² .

The "average acceleration of the applicator" is the average of the accelerations of the applicator during a back-and-forth movement.

This acceleration provides a pleasant feeling.

- The stiffness of the piston damper is between 300 N/m and 2000 N/m, preferably between 700 N/m and 1000 N/m. For a given state of stress or deformation, the ratio between the load and the deformation is referred to as "stiffness".

The damping is effective. The body surface is not subject to any impacts. All of these characteristics make it possible to obtain an application of a care product or makeup that imitates human gestures.

- The motor is housed in a casing.

The casing deadens the noise and vibrations of the motor.

The casing may comprise a shell, a ballast weight and a foam.

The shell may comprise a metal or plastics wall.

A "ballast weight" is a heavy material that reduces the noise and vibrations of the motor. The ballast weight may comprise a wire or balls.

The applicator may be set in movement by way of a motor equipped with a geared motor. This assembly inevitably generates low-frequency vibrations that are perceptible both in the form of vibrations in the hand and of noise. With the casing, these two components are reduced. Consumers are provided with real ease of use.

- The casing comprises a foam.

The foam can be a polyurethane, NBR, SBR or elastomer foam, for example. With a foam, a drastic reduction in the noise and vibrations of a device which essentially generates these is obtained. The controlled increase in weight of the motor by the addition of a ballast weight and the suspension thereof by a foam in the housing very substantially lowers the two parameters. The noise perceived is low. The user feels little in the way of vibrations in his/her hand.

The invention will be understood better from reading the following description, given solely by way of example, and with reference to the drawings, in which:

Figure 1 is a schematic and partial longitudinal section through the device according to the invention,

Figure 2 is a schematic and partial perspective side view of the device from Figure 1,

- Figure 3 is a schematic and partial perspective top view of a device according to the invention, comprising a casing. Figure 1 shows a device for applying a cosmetic product. Such a device is intended to apply a cosmetic product to a body surface of a user.

The cosmetic product is advantageously a makeup product, advantageously intended to be applied to a body surface of a user.

In a variant, the cosmetic product is a care product, in particular a face cream or body cream formula, a shampoo, a hair mask, a makeup removing oil, a treatment oil, a cleansing cream, an exfoliant, a mask or a sunscreen.

The body surface is for example the skin of a user, or keratin fibres such as hair, eyelashes or eyebrows.

The device shown in Figures 1 and 2 comprises:

- a grip 1 intended to be grasped manually by the user,

an applicator 2 that effects a back-and-forth movement along an axis X,

- a motor housed in the grip 1 ,

a cam mechanism 3 comprising a piston damper 4.

The motor can be powered by batteries, for example rechargeable batteries

(not shown in the figures). In a variant, it can be powered by a suitable electric current.

The motor can be turned on for example with the aid of a switch (not shown) situated on the grip 1 of the device.

The switch may be associated with a means for the user to adjust the back- and- forth speed of the applicator.

The rotational movement of the motor is transmitted to an output shaft Y of the motor. The output shaft Y of the motor is formed for example by a rod of axis Y that projects from the motor.

The output shaft of the motor can subsequently drive a cam mechanism 3. The applicator member has a flat surface 23 optionally designed to receive an applicator body for applying a cosmetic product, such as a foam for example, that is able to come into contact with the body surface of the user.

Thus, the applicator 2 is able to move in translation along the axis X in order to produce a back-and-forth movement between a rest position and an end-of-travel position.

The piston damper 4 is formed by: - a piston 40 comprising a partially hollow cylindrical part 41 defining a chamber 44 and a rod 42,

- a spring 5 having a stiffness of 800 N/m moving in the chamber 44.

The spring 5 is fixed:

- by a first end to the end wall 46 of the chamber 44, and

- by the other end to the outer surface 47 of the rod 42.

The spring can be fixed to the end wall 46 and to the outer surface 47 by adhesive bonding, by stapling or by welding.

In the rest position of the device, the spring 5 is in its position of maximum extension. The rod 42 is in its position of maximum distance from the end wall 46 of the chamber 44.

In the position of maximum action of the device, the spring 5 is in its position of maximum compression. The rod 42 is in its position of minimum distance from the end wall 46 of the chamber 44.

The spring 5 damps the movement of the rod 42.

The cam mechanism 3 comprises a cam 8 and a follower 70.

The follower 70 is essentially made up of two parts:

- a part 71 connected to the cam 8,

- the cylindrical part 41.

The part 71 comprises the rod 42 and a solid cylindrical part 72.

As a result of the follower 70 being split into two parts 71 and 41 that are connected together by a piston system, the movement of the follower 70 is damped. The vibrations of the follower 70 are reduced. The contact of the applicator member 2 with the skin is smooth, gentle and soft.

The follower 70 is housed in a sleeve 6.

The values of frequency, amplitude, speed and damping are automatically incorporated into the device in order to reproduce human gestures. The values allow perfect application of makeup that is most suitable for the user.

Generally chosen are:

- a frequency of 16 Hz,

- an amplitude of movement of the applicator member of 8 mm,

- an average acceleration of the applicator of 7 m/s ² . Thus, a device which:

is made to carry out an extremely quick movement of the "whiplash" type, allows a rapid back-and- forth movement,

has a large amplitude of movement and

damps the applicator so as to obtain a "soft" effect, is obtained.

The device shown in Figure 3 is identical to the one in Figures 1 and 2, except that a casing 12 has been added around the motor so as to reduce the noise and vibrations of the motor.

A series of measures are taken to demonstrate the effectiveness of the casing 12 in reducing the noise of the motor.

The casing 12 is formed by a ballast weight 9 and a shell 10.

The ballast weight 9 is a steel metal wire having a diameter equal to 1 mm and a length suitable for achieving a given mass.

The shell 10 is made of polyurethane.

Measuring method:

The noise is measured 10 cm from the surface 23 of the applicator 2. The noise is measured by a sonometer 13 sold by Testo under the reference 816.

The motor is of the geared motor type.

- The supply voltage of the motor,

- the mass of the ballast weight 9, and

- the total mass of the device are varied.

The mass of the shell 10 and the mass of the motor remain constant.

Results

The addition of the ballast weight 9 reduces the noise. Starting from 50 g of ballast weight 9, the noise is stable at 65 dBA for a voltage of 4 V. The invention is not limited to the examples illustrated. The features of the various examples can in particular be combined as parts of variants which are not illustrated. In particular, the follower 70 can have a different shape or different dimensions, and the cam 8 can be different, as can the applicator member 2.