TOOTHBRUSH HEAD AND MANUFACTURING METHOD

Abstract

A toothbrush head and manufacturing method, having a head with bristles that is coupled to a gripping handle, the head having two opposite bases, an outer one and an inner one, which are linked to each other by a central bridge that defines an intermediate separation space therebetween. There are a set of outer bristles and another set of inner bristles, which emerge facing each other from the respective inner faces of the opposite bases, and a set of central bristles emerging from the central bridge and perpendicular to the rest of bristles.

Description

OBJECT OF THE INVENTION

The present invention, toothbrush head, relates to a toothbrush head that has two opposite bases, an outer one and an inner one, which, linked to each other by a central bridge that defines an intermediate space therebetween, include respective sets of outer and inner bristles which emerge facing each other, there also being a third set of central bristles which emerge from the surfaces of the aforementioned joining bridge, with which said head enables the entire surface of the teeth to be brushed at the same time, effortlessly accessing both the upper portion thereof as well as the outer and inner portion. Likewise, the invention relates to the method for manufacturing 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 all oriented towards the same side.

Thus, although in some cases the aforementioned set of bristles may comprise groups of bristles with different lengths or different angles, to brush the surface of the teeth, to especially access the inner face of the same and of the molars in particular, it is necessary to perform operations for orienting the handle in order to correctly insert the head of the brush inside the open mouth so that said bristles access all the nooks and crannies of the inner portion of the teeth, making it difficult for most users to brush correctly and especially being a task of enormous difficulty for people with reduced mobility or for their caregivers.

Furthermore, the known brushes do not adapt to the anatomy of the mouth and teeth, having, as mentioned, bristles with wrong angles and lengths. Finally, brushes have been developed with teeth cleaning means or silicone bristles; however, these bristles have a great disadvantage caused by the material which results in very thick, soft bristles that do not enable them to be inserted into interdental spaces. Likewise, when they are inserted into 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 the function thereof.

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

Moreover, as a reference to the current state of the art, although many types of toothbrushes are known, at least the applicant is unaware of the existence of any other toothbrush which has technical and structural features equal or similar to those had by the one claimed herein.

DESCRIPTION OF THE INVENTION

A first object of the present invention is a toothbrush head according to claim 1. That which the invention proposes, as noted above, is a toothbrush whose head, instead of only having one base provided with a single set of bristles that all emerge oriented in the same direction for brushing the surface of the teeth, is distinguished by comprising two opposite bases, an outer base and an inner base, which are linked to each other by a central bridge that defines an intermediate space therebetween. 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 sets of bristles, one with outer bristles and another with inner bristles, which emerge facing each other from the respective inner faces of both bases, as well as a third set of central bristles that emerge from the central bridge, with which said head enables all surfaces of the teeth to be brushed at the same time, accessing both the upper portion thereof with the central bristles as well as the outer portion with the outer bristles and the inner portion with the inner bristles.

Preferably, the central bridge has a flat partition configuration wherein the central bristles emerge from the two opposite surfaces or faces thereof. Said central bridge, optionally, could be extendable, such that when specific pressure is exerted on the head of the brush, the length of the bridge will adapt to different tooth sizes, mainly the width thereof, adjusting the gap existing between the outer and inner bristles.

Furthermore, preferably, the outer bristles, associated with the inner face of the outer base, and the inner bristles, associated with the inner face of the inner base, are arranged so that they emerge from the surface of the outer base at a certain angle of inclination. In the case of the outer bristles, said angle is between 40° and 50°, preferably 45°, such that the outer surface of the tooth can be targeted with said inclination, as recommended by the brushing technique known as the “Bass technique”. Likewise, the inner bristles are inclined between 20° and 35°, preferably 30°, to target the inner surface of the teeth, as well as the gum line. The central bristles, located on the central partition, are also at an angle of between 40° and 50°, preferably 45°. These central bristles preferably have several faces, more preferably a frustopyramidal shape, the different faces of which enable brushing efficiency to be improved 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 coupling, with the aim of achieving the aforementioned angles in the bristles for optimal brushing of all tooth surfaces.

Preferably, the head comprises:

• • an outer part, made up of the outer base and a first reinforcing core, on which the outer base is injected,
  • an inner part, made up of the inner base, and a second reinforcing core, on which the inner base is injected,
  • a central bridge between the two bases and which determines a separation space between the inner faces of said bases,
  • and coupling means made up of a male element, arranged in one of the two cores, and a female element, arranged at one end of the bridge or in one of the two cores, for the coupling between the outer part and the inner part.

The bridge can be integrated into the outer base, into the inner base or be independent of both.

The first and second cores, in addition to enabling the coupling between the outer part and the inner part in some constructions, also give consistency and rigidity to the same, acting as a skeleton thereof. Likewise, the first core on which the outer part is injected has an outer end with means for coupling a handle to the toothbrush head.

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

Preferably, the outer and inner bases and central bridge with the respective sets of outer, inner and central bristles, which are part of the outer part and the inner part, are made of TPE (Thermoplastic Elastomer) or TPU (Thermoplastic Polyurethane), preferably TPU, by injection moulding, without discarding other materials such as SEBS (Polystyrene-ethylene-butadiene-styrene elastomer), or liquid silicone LSR, and the materials used have a hardness between 80 and 100 Shore A, preferably between 85 and 95 Shore A, thus ensuring correct rigidity in the bristles for dragging food debris between the teeth by the bristles, which enables the material to be injected at the same time. However, the choice of TPE or TPU, preferably TPU, for said parts is made based on the following advantages:

• • There is an FDA (Food and Drug Administration) certified food grade safe for this type of application.
  • It is recyclable.
  • Different hardnesses can be used so as to offer soft, medium and hard brushes.
  • There are hydrophobic characteristics which make it difficult for bacteria to appear.
  • An antibacterial additive can be added.
  • Moreover, in the case of TPU, it has low residual deformation; in other words, it returns to the initial position thereof after deformation, increasing the useful life of the brush.

TPU or TPE, preferably in TPU, injection manufacturing of the aforementioned components enables the head to be manufactured according to a process that achieves the objectives for which it has been designed, 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 outer base and of the inner base can be 0 mm, enabling the different interdental spaces to be accessed,
  • 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, on the bristles of the inner base and the outer base,
  • 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 2.6 mm.

Moreover, 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 for manufacturing a toothbrush head according to claim 13.

The method for manufacturing the head object of the invention comprises the following steps:

• • Injection moulding of a first core,
  • Over-injection moulding of the outer base on the first core, obtaining the outer part,
  • Injection moulding of a second core,
  • Over-injection moulding of the inner base on said second core, obtaining the inner part,
  • Assembly of the outer part and the inner part.

The mechanical assembly is carried out by tongue-and-groove means when inserting the second body into the first body, although it could also be the other way around, i.e., the first body into the second body. The coupling is preferably carried out by clipping one part inside another, achieving a coupling that is not reversible, in other words, it does not enable both bodies to be separated, unless a separation force much greater than the force for inserting one part into the other is applied.

The preferred coupling mechanism for joining the two bodies is a clip, loop, snap-fit or press-fit. In this type of mechanism, the two bodies fit together through the elastic deformation of at least one of the bodies so that interference occurs therebetween when at least one male element is inserted into at least one female element. At least one of the two bodies has interfering means such that when the male element is inserted into the female element, at least one of the two is temporarily deformed to overcome the interfering means, and after overcoming them, it returns to the undeformed situation thereof, leaving the male element coupled in the female element.

The locking of both bodies is permanent to prevent both from separating and prevent the coupling from being disassembled, releasing the lock, when the toothbrush is being used, with the consequent risk for the user of the brush. Likewise, there may or may not be a relative movement between both bodies, such that it enables the bridge to be extended in order to adapt to different tooth sizes or, on the contrary, that the length of the bridge is fixed. Said extension of the bridge can be due to the elastic characteristics of the material of the same bridge 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 parts, this coupling can be strengthened 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 press-fit coupling are located:

• • The second core, associated with the inner part, has at least one male element that is inserted into the first core, integrated into the outer part with the incorporated bridge, and which has at least one female element into which it is inserted and the male element of the second core remains permanently coupled by pressure.
  • The second core, associated with the inner part, has at least one male element that is inserted into the outer part with the incorporated bridge and which has at least one female element, independent of the first core, into which it is inserted and the male element of the second core remains permanently coupled.
  • The second core, associated with the inner part, has at least one female element that is inserted into the first core, integrated into the outer part with the incorporated bridge, and which has at least one male element into which it is inserted and the male element of the second core remains permanently coupled by pressure.

The previous constructions can also be given by alternating the position of the female and male elements of the press coupling, in other words:

• • The second core, associated with the inner part with the incorporated bridge, has at least one female element into which the first core is inserted, integrated into the outer part and which has at least one male element that is inserted and remains permanently coupled in the female element of the second core by pressure.
  • The second core, associated with the inner part with the incorporated bridge, has at least one female element independent of the second core, into which the outer part is inserted with at least one male element and remains permanently coupled in the female element of the second core.
  • The second core, associated with the inner part with the incorporated bridge, has at least one male element that is inserted into the first core, integrated into the outer part, and which has at least one female element into which it is inserted and the male element of the second core remains permanently coupled by pressure.

After the manufacture and coupling therebetween of the first body, outer body, first portion or outer portion of the head and the second body, inner body, second portion or inner portion of the head, both the first core and the second core are hidden, such that the inner and outer bases, being made of TPE/TPU, make it easier to adapt to different tooth and gum thicknesses, as well as to different dental anatomies. The central bridge, incorporated in the inner part or the outer part, and therefore also made of TPE/TPU, is also flexible so that it can open and thus adapt to different molar sizes.

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

For the latter, the coupling between the outer and inner body of the head can be extendable thanks to the existence of an inner guide in the central bridge with an elastic or accordion-shaped coupling that enables it to move longitudinally when a certain force is applied with the brush inside the mouth, creating the separation between the two portions of the head, and to return to the initial position thereof when said force is no longer applied.

It should be clarified that the designation of outer base, outer bristles, outer body or outer portion of the head and inner base, inner bristles, inner body or inner portion of the head means that, when using the brush on the teeth, the former are located on the outer side of the teeth and the latter on the inner side, enabling simultaneous brushing of both portions of the teeth as well as the upper portion by means of the central bristles found on the central bridge of the head.

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

DESCRIPTION OF THE DRAWINGS

To complete the description, and for the purpose of helping to make the features of the invention more readily understandable, this description is accompanied by a set of drawings constituting an integral part of the same, which by way of illustration and not limitation represents the following:

FIGS. 1 and 2 show bottom and top perspective views, respectively, of a first exemplary embodiment of the toothbrush object of the invention, specifically an example whose head comprises several parts that form parts that are joined by mechanical coupling, showing the general configuration and essential portions thereof.

FIGS. 3 and 4 show top and bottom perspective views, respectively, of the head of the brush of the invention shown in FIGS. 1 and 2, showing the portions and elements of said head in greater detail.

FIGS. 5 and 6 show top and bottom perspective views, respectively, of the head of the brush shown in FIGS. 3 and 4, in this case represented with the two portions that form it without coupling together and without the handle.

FIGS. 7 and 8 show top and bottom perspective views, respectively, of the head of the brush of the invention shown in the preceding figures.

FIG. 9 shows a cross-sectional view of the head of the brush, according to the C-C cut indicated in FIG. 8, showing the mechanical coupling between the two portions thereof.

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

FIG. 12 again shows a side elevation view of the brush head, similar to that shown in FIG. 11 with the central bridge in an extended position, in this case thanks to the accordion-shaped clasp.

FIG. 13 shows a front elevation view of the outer portion of the head of the invention, according to the example shown in FIGS. 1 to 12, showing the alternate inclination configuration, to the left and right, of the central bristles that emerge from one of the faces of the partition that makes up the central bridge.

FIG. 14 shows an exploded perspective view of the example of the brush of the invention shown in FIGS. 1 to 13.

FIG. 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 preceding figures.

FIG. 16 shows a perspective view of the head of another exemplary embodiment of the invention, in this case, an example in which said head is made up of several parts obtained by injection which are joined together by ultrasonic welding.

FIGS. 17 to 22 show respective views of the different parts that make up the head of the brush of the invention, according to the example shown in FIG. 15, showing the configuration thereof with and without the incorporated bristles.

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

FIGS. 24 to 26 show perspective views, respectively, of another exemplary embodiment of the brush of the invention, in this case an example in which said head is made up of a single part obtained by injection with the bristles joined to it by means of adhesive glue, said part being represented in FIG. 24 without the bristles, in FIG. 25 with the bristles glued to one of the sides of the part and in FIG. 26 once all the bristles have been glued.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the aforementioned figures, and in accordance with the adopted numbering, an exemplary embodiment of the toothbrush head of the invention can be seen therein.

Thus, as can be seen in said figures, the brush (1) comprises a head (2) with bristles (3) that is coupled to a gripping handle (4), said head (2) having two opposite bases, an outer one (5) and an inner one (6), which are linked to each other by means of a central bridge (7) that defines an intermediate separation space (8) therebetween, there being a set of outer bristles (3a) and another set of inner 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) emerging from the central bridge (7) and perpendicular to the surface of said bridge (7).

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

Preferably, the outer bristles (3a) which emerge from the outer 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 seen in FIG. 13, are alternatively oriented to the right and to the left.

In addition, optionally, the head (2) is extendable so that the intermediate separation space (8) between the outer base (5) with the outer bristles (3a) and the inner base (6) with the inner bristles (3b) adapts to the different tooth sizes when pressure is exerted during brushing, returning to the position thereof when said pressure is no longer exerted.

In an embodiment, such as that shown in FIGS. 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, press-fit, snap-fit or a loop.

Preferably, as can be seen in FIG. 14, in said embodiment, the head (2) comprises:

• • an outer part (9), made up of the outer base (5) with the outer bristles (3a) and the central bridge (7) with the central bristles (3b),
  • a first core (10), with an end with means for gripping the handle (4), and a coupling element, male or female, at the opposite end and on which said outer part (9) is injected, forming an outer portion or outer body (A) of the head,
  • an inner part (11), made up of the inner base (6) with the inner bristles (3b),
  • and a second core (12), with a male or female element, on which said inner part (6) is injected, forming an inner portion or inner body (B) of the head, and which enables the aforementioned mechanical coupling between both portions (A and B).

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

As can be seen in FIG. 9, the second core (12) of the inner portion or body (B) has a female element, in the form of anchoring tabs, into which the male element in the shape of an arrow is inserted, from the first core (10) of the outer portion (A) after being inserted into the central bridge (7) of the outer part (9). In this example, the bridge is incorporated into the outer part (9) but it could also be incorporated into the inner part (6).

Alternatively, the second core (12) of the inner portion or body (B), provided with anchoring tabs acting as a male element, is coupled with the outer part (9) of the outer portion or body (A), passing through holes (13) made for this purpose in the central bridge (7), as seen in FIG. 6. In this example, the bridge is incorporated into the outer part (9) but it could also be incorporated into the inner part (6), in which case, the first core would be the one to include the anchoring tabs for the coupling thereof to the bridge.

Preferably, the outer part (9) and the inner 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 outer portion (A), specifically the one that defines the outer base (5) and, in turn, defines the area peripheral to the portion of the first core (10) that has an end (14) for coupling the handle (4), being made of TPE/TPU, is flexible, which enables said portion to be adapted to different dental anatomies and, at the same time, the central bridge (7) is also flexible so that it is can open and thus adapt to different molar sizes.

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

Preferably, the joint between the outer portion (A) and the inner portion (B) of the head is extendable, so that the separation space (8) adapts to different tooth sizes (FIGS. 10 and 11) by means of an inner guide (15) of the central bridge (7), with an elastic clasp (FIG. 11) or with an accordion-shaped element (16) (FIG. 12), which enables it to move longitudinally when a certain force is applied and return to the initial position thereof when the force is no longer applied.

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

FIG. 15 shows an alternative brush, similar to that of FIG. 14, in which the head has slight modifications with respect to the head shown and described in said figure and it also shows coupling means between the first part and the handle different from those shown. Specifically, in this example, the core (10) has at the end (14) thereof two projections (14a) with through holes. Arranged between said two projections (14a) is the end (4d) of the handle (4) which has a hollow coinciding with the through holes of the projections (14a) at the end (14) of the core (10). To ensure the position between the elements, a pin (4c) is inserted which passes through the through holes in the end (14a) of the core (10) and the hollow end (4d) of the handle (4). In this way, it also enables the handle (4) to be rotated with respect to the head of the brush (1).

In FIGS. 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 outer base (5) made of ABS, PA or PET, obtained by injection moulding, with outer bristles (3a) made of TPU, TPE or LSR over-injected on said base (5),
  • a central bridge (7), made of ABS, PA or PET, obtained by injection moulding, with the central bristles (3c) made of TPU, TPE or LSR over-injected on the same,
  • and an inner base (6) made of ABS, PA or PET, obtained by injection moulding, with inner bristles (3b) made of TPU, TPE or LSR over-injected on said base (6), the two bases, outer (5) and inner (6), being joined to the respective ends of the central bridge (7) by ultrasonic welding.

In FIGS. 24 to 26, it can be seen how in another embodiment of the brush (1), the head (2) is made up of a single monobloc part (17) made of plastic material obtained by injection, into which the outer base (5), the central bridge (7) and the inner base (6) are integrated, and which incorporates the respective sets of outer bristles (3a), central bristles (3c) and inner bristles (3b) made of TPU, TPE or LSR and joined to said part by adhesive glue.

In these last two embodiments, as in the previous ones, for the coupling of the handle (4) to the head (2) of the brush (1), the outer base (5) has an end (14), it being envisaged, in any of the embodiments described, that said coupling between the head (2) and the handle (4) can be mobile in order to enable the relative movement between both portions of the brush (1).

Claims

1. A toothbrush head, comprising an outer base and an inner base, each with an inner face and an outer face, at least the inner face of one of said bases with a central bridge that defines an intermediate separation space between both inner faces, and having cleaning elements which emerge from the respective facing inner faces of said bases and from the surface of the central bridge further comprising:

a first reinforcing core integrated inside the outer base, said first core and said outer base forming an outer part,

a second reinforcing core integrated inside the inner base, said second core and said inner base forming an inner part, and

both bases linked to each other by the central bridge,

at least one of said cores having a male element, for coupling within the central bridge with a female element arranged in the part opposite to that of the male element, therefore linking the outer base and the inner base, and

said first core comprises on the outer base, at the end opposite the coupling with the inner part, coupling means for a handle.

2. The head, according to claim 1, wherein the male element and the female element are press-fit or snap-fit coupling means.

3. The head, according to claim 1, wherein the coupling between the male element and the female element comprises adhesive or an ultrasonic welding.

4. The head, according to claim 1, wherein the head is extendable so that the intermediate separation space between the outer base and the inner base adapts to different tooth sizes when pressure is exerted during brushing, returning to the position thereof when said pressure is no longer exerted.

5. The head, according to claim 1, wherein one of the two cores comprises two anchoring tabs as a male element for coupling thereof in two holes made for this purpose in the central bridge.

6. The head, according to claim 1, wherein one of the two cores comprises a male element for coupling thereof in a female element arranged on the core opposite to that of the male element.

7. The head, according to claim 1, wherein the cleaning elements are bristles.

8. The head, according to claim 7, wherein the bristles of the central bridge emerge from the two faces thereof at an angle of 45 degrees.

9. The head, according to claim 7, wherein the bristles of the outer base have an angle of inclination of between 40° and 50° with respect to the inner face of said base and the inner base has an angle of inclination less than 35° with respect to the inner face of said base.

10. The head, according to any of claim 1, wherein the components thereof are injection parts.

11. The head, according to claim 1, wherein the outer part and the inner part are made of TPE or TPU.

12. The head, according to claim 1, wherein the cores are made of PP, PC or ABS.

13. (canceled)

14. The head, according to claim 1, wherein said coupling means enable the handle to move with respect to the outer base.

15. A method for manufacturing a head, according to claim 1, comprising the following steps:

injection moulding of a first core,

over-injection moulding of the outer base on the first core, obtaining an outer part,

injection moulding of a second core,

over-injection moulding of the inner base on said second core, obtaining an inner part,

assembly of the first part and the second part by coupling both parts within a central bridge between the outer base and the inner base.