WO2022184954A1

WO2022184954A1 - Toothbrush head and manufacturing method

Info

Publication number: WO2022184954A1
Application number: PCT/ES2022/070108
Authority: WO
Inventors: Paul Victoria Mancy; Carlos Martín Gascón
Original assignee: Ziz Dental Care S.L.
Priority date: 2021-03-05
Filing date: 2022-03-01
Publication date: 2022-09-09
Also published as: EP4052608A1; US20240148132A1

Abstract

The invention relates to a toothbrush head and a manufacturing method, consisting of a head with bristles (3) that is coupled to a gripping handle (4), said head (2) comprising two opposing bases, an outer one (5) and an inner one (6), which are connected to each other by means of a central bridge (7) defining an intermediate separation space (8) therebetween, a set of outer bristles (3a) and a set of inner bristles (3b) emerging towards each other from the respective inner faces of said opposing bases (5, 6), and a set of central bristles (3c) emerging from the central bridge (7), perpendicularly to the rest of bristles (3a, 3b).

Description

HEAD FOR TOOTHBRUSH AND MANUFACTURING METHOD

DESCRIPTION

OBJECT OF THE INVENTION

The present invention, toothbrush head, refers to a toothbrush head that has two opposite bases, one external and one internal, which, linked together by a central bridge that defines an intermediate space between them, include respective sets of bristles, external and internal, that emerge facing each other, and there is also a third set of central bristles that emerge from the surfaces of the aforementioned union bridge, with which said head allows brushing the entire surface of the teeth at the same time , effortlessly accessing both its upper part and the external and internal parts. Likewise, the invention refers to the manufacturing method of said head.

The field of application of the present invention falls within the sector of the industry dedicated to the manufacture of toothbrushes.

BACKGROUND OF THE INVENTION

Currently, toothbrushes, although they can have different designs, are usually made up of a head that includes a single base with a single set of bristles oriented, all of them, towards the same side.

Thus, although in some cases the aforementioned set of bristles may include groups of bristles of different lengths or different angles, to brush the surface of the teeth, especially to access their inner face and in particular the molars, it is necessary to perform handle orientation operations to achieve the correct insertion of the brush head inside the open mouth so that these bristles access all the nooks and crannies of the inner part of the teeth, making correct brushing difficult for most users and especially being a extremely difficult task for people with reduced mobility or for their caregivers.

Likewise, known brushes do not adapt to the anatomy of the mouth and teeth, presenting, as mentioned, bristles with wrong angles and lengths. Lately, brushes have been developed with means for cleaning teeth or silicone bristles, but these have a great disadvantage derived from the material that results in very thick and soft bristles that do not allow their introduction into interdental spaces. Likewise, when they are introduced in said spaces, the low hardness of the silicone material used, between 50 and 70 Shore A, prevents the bristles from dragging the material and fulfilling their function.

The objective of the present invention is, therefore, to provide a toothbrush and head that avoids said problem and facilitates said access, avoiding such maneuvers by developing a head with bristles oriented so that they reach all sides of the tooth at the same time. all the teeth in the mouth and to the gum line, without it being necessary to arrange the handle in awkward positions or without having to open the mouth wide to do so.

On the other hand, and as a reference to the current state of the art, although many types of toothbrushes are known, at least by the applicant, the existence of none that has technical and structural characteristics equal to or similar to those described is unknown. presents the one claimed here.

EXPLANATION OF THE INVENTION

The present invention has as its first object a head for a toothbrush according to claim 1. What the invention proposes, as has been pointed out above, is a toothbrush whose head, instead of only having a base provided with a unique set of bristles that emerge all oriented in the same direction to brush the surface of the teeth, it is distinguished by comprising two opposite bases, an external base and an internal base, which are linked to each other by a central bridge that defines an intermediate space between both. Integrated into the inner faces of the bases are cleaning elements, preferably bristles, which will be in contact with the teeth and gums. In this way, there are two separate sets of bristles, one of external bristles and another of internal bristles, which emerge facing each other from the respective internal faces of both bases, as well as a third set of central bristles that emerge from the central bridge, with what which said head allows brushing all the surfaces of the teeth at the same time, accessing both the upper part with the central bristles and the external part with the external bristles and the internal part with the internal bristles.

Preferably, the central bridge has a configuration in the form of a flat partition where the central bristles emerge from its two opposite surfaces or faces. Said central bridge, optionally, may be extendable, so that by exerting some pressure on the brush head, the length of the bridge will adapt to the different sizes of teeth, mainly to their width, adjusting the existing separation between the external and internal bristles.

In addition, preferably, the external bristles, associated with the internal face of the external base, and the internal bristles, associated with the internal face of the internal base, are arranged in such a way that they emerge from the surface of the external base with an angle of inclination. certain. In the case of external bristles, said angle is between 40° and 50°, preferably 45°, so that they allow attacking the outer surface of the tooth with said inclination, as recommended by the brushing technique known as the "Bass technique". . Likewise, the internal bristles have an inclination of between 20° and 35°, preferably 30°, to attack the inner surface of the teeth, as well as the gum line. The central bristles, located in the central partition, also have an angle between 40° and 50°, preferably 45°. These central bristles preferably have several faces, more preferably a truncated-pyramidal shape, the different faces of which make it possible to improve brushing efficiency as the brush moves from left to right inside the mouth.

The head of the brush of the invention is made up of several components obtained by injection, and which are assembled together by means of coupling elements, preferably mechanical, with the aim of achieving the mentioned angles in the bristles for optimal brushing of all the surfaces of the brush. tooth.

Preferably, the head comprises: an external part, formed by the external base and a first reinforcement core, on which the external base is injected, an internal part, formed by the internal base, and a second reinforcement core on which the internal base is injected, a central bridge between the two bases and that determines a separation space between the internal faces of said bases,

- and coupling means made up of a male element, arranged in one of the two souls, and a female element, arranged at one end of the bridge or in one of the two souls, for the coupling between the external part and the internal part .

The bridge can be integrated in the external base, in the internal base or be independent of both.

The souls, first and second, in addition to allowing, in some of the constructions, the coupling between the external piece and the internal piece, also give consistency and rigidity to it, acting as their skeleton. Likewise, the The first core on which the external part is injected has an external end with means for coupling a handle to the head of the toothbrush.

The outer, inner, and center bristles are preferably integrated into the inner face of the outer base, the inner face of the inner base, and the bridge surfaces during injection thereof, although it is also possible, though not desirable, incorporate said bristles in subsequent manufacturing procedures by means of different techniques such as, for example, ultrasound, adhesives or even mechanical bonding.

Preferably the external and internal bases and central bridge with the respective sets of external, internal and central bristles, which form part of the external part and the internal part, are made of TPE (Thermoplastic Elastomer) or TPU (Thermoplastic Polyurethane), preferably TPU, by injection molding, without ruling out other materials such as SEBS (polystyrene-ethylene-butadiene-styrene elastomer), or LSR liquid silicone, with a hardness of the materials used between 80 and 100 Shore A, preferably between 85 and 95 Shore A, thus ensuring a correct rigidity in the bristles for the dragging of food remains between the teeth by the bristles, while allowing the injection of the material. However, the choice of TPE or TPU, preferably TPU, for these pieces is given by the following advantages:

There is FDA certified food grade, (Food and Drug Administration) safe for this type of application.

It is recyclable.

- Different hardnesses can be used to offer soft, medium and hard brushes.

- Hydrophobic characteristics which hinders the appearance of bacteria.

- An antibacterial additive can be added.

- In addition, in the case of TPU, it has low remaining deformation, that is, it returns to its initial position after its deformation, increasing the life of the brush.

The manufacture by injection in TPU or TPE, preferably in TPU, of the aforementioned components allows the head to be manufactured according to a procedure that allows the objectives for which it has been designed to be achieved, specifically:

- Angle of the bristles on the inner face of the outer base between 40° and 50°, preferably 45°, - Angle of the bristles on the inner face of the inner base between 20 and 35°, preferably 30°,

Distance between the facing bristles of the external base and the internal base can be as little as 0 mm, allowing access to the different interdental spaces,

Hardness of the bristle material between 80 and 100 Shore A, preferably between 85 and 95 Shore A, in order to have different hardnesses depending on the need for brushing, guaranteeing access to the different interdental spaces regardless of the thickness of the bristles. bristles, on the inner base and outer base bristles,

A thickness of the bristles of the inner and outer base, between 0.5 mm and 1 mm, with a decreasing thickness from the inner face towards the free ends of the bristles,

A thickness of the central bristles, preferably with a frustopyramidal shape, which preferably varies between a length of between 2.1 and 3.8 mm, a width of between 0.5 and 0.8 mm and a height of between 1 and 2, 6mm

For their part, the reinforcing cores are preferably made of PP (Polypropylene), PC (Polycarbonate) or ABS (Acrylonitrile Butadiene Styrene).

A second object of the invention is a method of manufacturing a toothbrush head according to claim 13.

The manufacturing method of the head object of the invention comprises the following stages:

Injection mold of a first soul,

- Over-injection in mold of the external base on the first soul, obtaining the external part,

Mold injection of a second soul,

- Injection molding of the internal base on said second soul, obtaining the internal part,

Assembly of the external part and the internal part.

The mechanical assembly is done by tongue and groove when inserting the second body into the first body, although it could also be the other way around, that is, the first body into the second body. The coupling is preferably carried out by clipping one piece inside another, achieving a coupling that is not reversible, that is to say, that it does not allow the separation of both bodies, unless a separation force much greater than the force for the introduction of one piece inside the other is applied.

The preferred coupling mechanism to join both bodies is clip, latch, snap-fit or press-fit type. In this type of mechanism, the two bodies fit together through the elastic deformation of at least one of the bodies so that interference between them is produced by inserting at least one male element into at least one female element. At least one of the two bodies has interference means so that when the male element is inserted into the female element, at least one of the two is temporarily deformed to overcome the interference means and after overcoming them it returns to its undeformed position, remaining coupled the male element in the female element.

The lock between both bodies is permanent to prevent both from separating and the coupling being disassembled, releasing the lock, during the use of the toothbrush with the consequent risk for the user of the brush. Likewise, between both bodies there may or may not be a relative movement, in such a way that it allows the extension of the bridge to adapt to different sizes of teeth or, on the contrary, the length of the bridge is fixed. Said extension of the bridge may be due to the elastic characteristics of the material of the bridge itself or to elastic means arranged in the coupling between both bodies or to telescopic means arranged in the coupling between both bodies.

Alternatively, after the male-female coupling between both pieces, it can be consolidated by means of an adhesive or ultrasonic welding.

In accordance with the above, there are different possibilities for manufacturing and assembling the head depending on where the male and female elements of the clip, snap-fit or pressure-fit coupling are located:

The second soul, associated with the internal part, has at least one male element that is inserted into the first soul, integrated in the external part with the built-in bridge, and which has at least one female element in which it is inserted and is coupled the male element of the second soul, by pressure permanently.

The second core, associated with the internal part, has at least one male element that is inserted into the external part with the built-in bridge and has at least one female element, independent of the first soul, in which the male element of the second soul is inserted and permanently attached.

The second soul, associated with the internal part, has at least one female element that is inserted into the first soul, integrated in the external part with the built-in bridge, and which has at least one male element in which it is inserted and remains coupled. the male element of the second soul, by pressure permanently.

The previous constructions can also be given by alternating the position of the female and male elements of the pressure coupling, that is:

The second soul, associated with the internal part with the built-in bridge, has at least one female element in which the first soul is inserted, integrated in the external part and which has at least one male element that is inserted and remains coupled in the female element of the second core, permanently pressed.

The second soul, associated with the internal part with the built-in bridge, has at least one female element independent of the second soul, in which the external part is inserted with at least one male element and is permanently attached to the female element. of the second soul.

The second soul, associated with the internal part with the built-in bridge, has at least one male element that is inserted into the first soul, integrated in the external part, and which has at least one female element in which it is inserted and is coupled. the male element of the second soul, by pressure permanently.

After the manufacture and coupling together of the first body, external body, first part or external part of the head and the second body, internal body, second part or internal part of the head, both the first and second souls are hidden, so that The internal and external bases, being made of TPE/TPU, facilitate adaptation to different thicknesses of teeth and gums, as well as to different dental anatomies. The central bridge, incorporated in the internal part or in the external part, and therefore also made of TPE/TPU, is also flexible so that it can be opened and thus adapted to different sizes of molars.

Likewise, and as anticipated, the separation between the external and internal base of the brush head may vary depending on the end user depending on the size of the teeth, or the head itself can include telescopic means in the bridge and coupling between both outer and inner bodies.

For the latter, the coupling between the external and internal body of the headstock can be extensible thanks to the existence of an internal guide in the central bridge with elastic or accordion-shaped coupling that allows it to move longitudinally when a certain force is applied with the brush inside the mouth, causing the separation between the two parts of the head, and which returns to its initial position when said force is no longer applied.

It should be clarified that the designation of external base, external bristles, external body or external part of the head and internal base, internal bristles, internal body or internal part of the head is due to the fact that, when using the brush on the teeth, the former are located on the external side of the teeth and the second on the internal side, allowing simultaneous brushing of both parts of the teeth as well as the upper part through the central bristles found in the central bridge of the head.

Finally, it should be noted that, in any of the options described, the external body of the head, through the external base, may be attached to the handle by means of a fixed joint or by means of an articulated joint, which allows a certain movement of said head with respect to of the handle to further improve the accessibility of the handle to all parts of the denture. The coupling between the handle and the head is preferably carried out through the first core on which the external part is over-injected, since said core has an outer end, opposite the end of coupling to the inner part, when the first core is inserted. It is used as a coupling body, which incorporates means for coupling the handle.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, a set of plans is attached to this specification, as an integral part of it, in which for illustrative and non-limiting, the following has been represented:

Figures number 1 and 2 show respective views, in lower and upper perspective respectively, of a first example of embodiment of the toothbrush object of the invention, specifically an example whose head comprises several pieces that form respective parts that are joined by coupling mechanic, appreciating his general configuration and essential parts.

Figures 3 and 4 show respective top and bottom perspective views, respectively, of the head of the brush of the invention shown in figures 1 and 2, showing the parts and elements of said head in greater detail. Figures number 5 and 6 show respective views, in upper and lower perspective, respectively, of the brush head shown in figures 3 and 4, in this case represented with the two parts that form it without coupling to each other or to the handle.

Figures number 7 and 8 show respective views, in upper and lower plan, respectively, of the head of the brush of the invention shown in the preceding figures.

Figure number 9 shows a sectional view of the brush head, according to section C-C indicated in figure 8, showing the mechanical coupling between the two parts thereof.

Figures 10 and 11 show respective views, in side elevation, of the head of the brush of the invention, according to the example shown in figures 1 to 9, represented with the central bridge in the retracted and extended position, respectively, by elastic coupling.

Figure number 12 again shows a side elevational view of the brush head, similar to the one shown in figure 11 with the central bridge in an extended position, in this case thanks to an accordion-shaped hook.

Figure number 13 shows a front elevation view of the external part of the head of the invention, according to the example shown in figures 1 to 12, showing the configuration of alternating inclination, left and right, of the central bristles that emerge from one of the faces of the partition that forms the central bridge. Figure number 14 shows an exploded perspective view of the example of the brush of the invention shown in figures 1 to 13.

Figure number 15 shows an alternative construction of a head according to the present invention with a handle coupled to the outer part with means different from those shown in the previous figures. Figure number 16 shows a perspective view of the head of another embodiment of the invention, in this case, an example in which said head is made up of several parts obtained by injection that are joined together by ultrasonic welding.

Figures number 17 to 22 show respective views of the different pieces that make up the head of the brush of the invention, according to the example shown in Figure 15, showing their configuration with and without incorporated bristles.

Figure number 23 shows a perspective view of the three pieces that make up the brush head, according to the example shown in figure 16, represented once the bristles have been incorporated and prior to joining them by ultrasonic welding.

And figures number 24 to 26 show perspective views of another embodiment of the brush of the invention, in this case an example in which said head is formed by a single piece obtained by injection with the bristles attached to it by means of adhesive glue, having represented in figure 24 said piece without the bristles, in figure 25 with the bristles glued on one of the sides of the piece and in figure 26 once all the bristles have been glued.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the aforementioned figures, and according to the adopted numbering, an example of embodiment of the toothbrush head of the invention can be seen in them

Thus, as can be seen in said figures, the brush (1) comprises a head (2) with bristles (3) that is coupled to a holding handle (4), said head (2) presenting two opposite bases, one external (5) and an internal (6), which are linked to each other by a central bridge (7) that defines an intermediate space (8) separating them, with a set of external bristles (3a) and another set of internal bristles (3b), which emerge facing each other from the respective inner faces of said opposite bases (5, 6), as well as a set of central bristles (3c) that emerge from the central bridge (7) and perpendicular to the surface of said bridge (7).

Preferably, the central bridge (7) has a flat partition-shaped configuration with central bristles (3c) emerging from their respective opposite faces.

Preferably, the external bristles (3a) that emerge from the external base (5) are arranged at an angle of inclination of about 45° with respect to said base (5).

Preferably, the central bristles (3c) also emerge from the two faces of the central bridge (7) at an angle of 45 degrees and, as can be seen in figure 13, they are oriented alternately to the right and to the left. Furthermore, optionally, the head (2) is extensible so that the intermediate space (8), separating the external base (5) with the external bristles (3a) and the internal base (6) with the internal bristles (3b), adapts to the different sizes of teeth by exerting pressure during brushing, returning to its position when the pressure is released.

In an embodiment, such as the one shown in figures 1 to 14, the described head (2) of the brush (1) is made up of various parts obtained by injection and assembled together by mechanical coupling, by pressure or snap-fit. fit or clip

Preferably, as shown in figure 14, in said embodiment, the head (2) comprises: an external part (9), formed by the external base (5) with the external bristles (3a) and the central bridge ( 7) with the central bristles (3b), a first core (10), with one end with means for holding the handle (4) and at the opposite end a coupling element, male or female, and on which is injected said external part (9), forming an external part or external body (A) of the head, an internal part (11), formed by the internal base (6) with the internal bristles (3b),

- and a second soul (12), with a male or female element, on which said internal part (6) is injected, forming an internal part or internal body (B) of the head, and which allows the aforementioned mechanical coupling between both parts (A and B).

The coupling between both cores (10, 12) is carried out by inserting a male element into a female element, said male element or female element being arranged in one or the other core.

As can be seen in Figure 9, the second soul (12) of the internal part or body (B) has a female element, in the form of anchor nails, in which the male element in the form of an arrow is inserted, of the first soul (10) of the external part (A) after being inserted in the central bridge (7) of the external part (9). In this example, the bridge is incorporated in the external part (9) but it could also be incorporated in the internal part (6).

Alternatively, the second soul (12) of the internal part or body (B), provided with anchoring nails acting as a male element, is coupled with the external part (9) of the external part or body (A), passing through holes (13) made for this purpose in the central bridge (7), as shown in figure 6. In this example, the bridge is incorporated in the external part (9) but it could also be incorporated into the internal piece

(6), in which case, it would be the first web that would include the anchoring nails for its coupling to the bridge.

Preferably, the external part (9) and the internal part (11) are made of TPE or TPU and the first and second cores (10, 12) are made of PP, PC or ABS.

With this, the peripheral surface of the external part (A), specifically the one that defines the external base (5) and, in turn, defines the peripheral zone to the part of the first core (10) that has an end ( 14) to couple the handle (4), being made of TPE/TPU, it is flexible, which allows the adaptation of said part to different dental anatomies and, at the same time, the central bridge (7) is also flexible so that it can be can open and thus adapt to different sizes of molars.

The external part (9) is over-injected to the first soul (10), obtained in turn previously by injection, forming the external part or body (A) of the head, and the internal part (11) is over-injected to the second soul ( 12) which is also a piece previously obtained by injection, forming the internal part or body (B).

Preferably, the connection between the external part (A) and the internal part (B) of the head is extensible, so that the separation space (8) adapts to different tooth sizes (figures 10 and 11) by means of an internal guide ( 15) center bridge

(7), with elastic coupling (figure 11) or with an accordion-shaped element (16) (figure 12), which allows it to move longitudinally when a certain force is applied and returns to its initial position when said force is no longer applied. strength.

Referring to figure 14, it can be seen how, in the described embodiment, the handle (4) preferably comprises a core (4a) obtained by injection of PP, PC or ABS, with a cover (4b) over-injected of TPE or TPU. The coupling end (4d) of the handle with the end (14) of the core (10) has lateral recesses in which complementary projections existing on the external base (5) are inserted and associated with projections on the end (14) of the core (10), as can be seen in greater detail in figure 5.

Figure 15 shows an alternative brush, similar to that of figure 14, in which the head has slight modifications with respect to the head shown and described in said figure and also shows coupling means between the first piece and the handle different from those shown. . Specifically, in this example, the soul (10) It has two projections (14a) with through holes at its end (14). Between said two projections (14a) the end (4d) of the handle (4) is arranged, which has a hole coinciding with the through holes of the projections (14a) of the end (14) of the core (10). To ensure the position between the elements, a pin (4c) is introduced which passes through the through holes of the end (14a) of the core (10) and the hollow end (4d) of the handle (4). In this way, the rotation of the handle (4) with respect to the brush head (1) is also allowed.

Looking at figures 16 to 23, it can be seen how, in another embodiment, the head (2) of the brush (1) of the invention is made up of several parts obtained by injection and joined together by ultrasonic welding. Preferably, in said embodiment, the head (2) comprises:

- an external base (5) of ABS, PA or PET, obtained by injection molding, with external bristles (3a) of TPU, TPE or LSR superinjected into said base (5),

- a central bridge (7), in ABS, PA or PET, obtained by injection molding, with the central bristles (3c) in TPU, TPE or LSR superinjected therein,

- and an internal base (6) of ABS, PA or PET, obtained by mold injection, with internal bristles (3b) of TPU, TPE or LSR superinjected into said base (6), with the two bases being external (5) and internal (6), joined to the respective ends of the central bridge (7) by means of ultrasonic welding.

Referring to figures 24 to 26, it can be seen how in another embodiment of the brush (1), the head (2) is made up of a single one-piece piece (17) of plastic material obtained by injection, in which the base is integrated. external (5), the central bridge (7) and the internal base (6), and incorporating the respective sets of external bristles (3a), central bristles (3c) and internal bristles (3b) made TPU, TPE or LSR and that are attached to said piece by means of adhesive glue.

In these last two forms of embodiment, as in the previous ones, for the coupling of the handle (4) to the head (2) of the brush (1), the external base (5) has an end (14), having been provided, in any of the embodiments described, that said coupling between the head (2) and the handle (4) can be mobile to allow relative movement between both parts of the brush (1).

Claims

1. Toothbrush head, comprising an external base (5) and an internal base (6), each with an internal face and an external face, at least the internal face of one of said bases (5, 6) with a central bridge (7) that defines an intermediate space (8) separating both internal faces, and presenting cleaning elements (3a, 3b, 3c) that emerge from the respective facing internal faces of said bases (5, 6) and the surface of the central bridge (7), characterized in that it also comprises:

A first reinforcing core (10) integrated inside the external base

(5), forming said first soul (10) and said external base (5) an external part (9),

A second reinforcing core (12) integrated inside the internal base

(6) forming said second soul (12) and said internal base (6) an internal part (11), presenting at least one of said souls (10, 12) a male element for coupling with a female coupling element arranged in the part (9, 11), opposite to the one with the male element.

2. Head, according to claim 1, characterized in that the male element and the female element are pressure-fit or snap-fit coupling means.

3. Head, according to claim 1, characterized in that the coupling between the male element and the female element comprises adhesive or ultrasonic welding.

4. Head, according to any of the preceding claims, characterized in that the head (2) is extensible so that the intermediate space (8), separating the external base (5) and the internal base (6), adapts to different sizes of teeth by exerting pressure during brushing, returning to their position when the pressure is released.

5. Head, according to any of the preceding claims, characterized in that one of the two souls comprises two anchoring nails as a male element for coupling to two holes (13) made for this purpose in the central bridge (7).

6. Head, according to any of claims 1 to 5, characterized in that one of the two cores comprises a male element for coupling to a female element arranged in the core opposite to the one with the element male.

7. Head, according to claim 1, characterized in that the cleaning elements (3a, 3b, 3c) are bristles.

8. Head, according to claim 7, characterized in that the bristles (3c) of the central bridge (7) emerge from its two faces at an angle of 45 degrees.

9. Head, according to claim 7, characterized in that the bristles of the external base (5) have an angle of inclination of between 40° and 50° with respect to the internal face of said base (5) and the bristles of the internal base ( 6) have an angle of inclination less than 35° with respect to the internal face of said base (6).

10. Head, according to any of the preceding claims, characterized in that its components are injection parts.

11. Head, according to any of the preceding claims, characterized in that the external part (9) and the internal part (11) are made of TPE or TPU.

12. Head, according to any of the preceding claims, characterized in that the cores are made of PP, PC or ABS.

13. Head, according to any of the preceding claims, characterized in that the first soul (10) comprises on the external base (5), at the end opposite the one for coupling with the internal part (11), coupling means for a handle (two).

14. Head, according to claim 13, characterized in that said coupling means allow the movement of the handle with respect to the outer base (5).

15. Method of manufacturing a head, according to any of the preceding claims, characterized in that it comprises the following steps:

Injection molding of a first soul, - Superinjection molding of the external base on the first soul, obtaining an external part,

Mold injection of a second soul,

- Injection molding of the internal base on said second core, obtaining an internal piece, - Assembly of the first piece and the second piece.