WO2012035490A1

WO2012035490A1 - A toothbrush head

Info

Publication number: WO2012035490A1
Application number: PCT/IB2011/053993
Authority: WO
Inventors: Lorenzo Mazza
Original assignee: Lorenzo Mazza
Priority date: 2010-09-14
Filing date: 2011-09-13
Publication date: 2012-03-22
Also published as: ITBO20100556A1; EP2615940A1

Abstract

A toothbrush head (100) comprises: a body (1), having a front face (2) and a rear face (3); a plurality of housings (5), provided between the front face (2) and rear face (3); a plurality of bristle tufts (6), mounted slidably in axial direction in a corresponding housing (5) and extending from the front face (2); elastic means (7), associated to the bristle tufts (6), so as to allow the same to slide axially along their housings (5), toward the inside of the toothbrush head (100), by effect of a push action exerted on their outer end (6a). The elastic means (7) comprises, for each of the bristles tufts (6), an elastic band (17), fastened to the bristles tuft (6) at or near the inner side (6b) thereof, and acting through the body (1) inside a corresponding seat (18).

Description

A TOOTHBRUSH HEAD

Technical Field

The present invention relates to the technical field concerning products for the oral hygiene.

In particular, the invention relates to a toothbrush head which can be used both for manual and electric devices.

Background Art

It is known that the heads of commonly used toothbrush comprise a body, to which a plurality of bristle tufts are fastened. A terminal portion of each tuft is placed inside a hole made in a face of the head and is fastened in place by glue or by other known systems.

The tufts are formed by groups of bristles, arranged side by side, having approximately the same length, kept well close one to another. A number of tufts extend from the head face substantially parallel one to another. The length of each tuft is calculated in accordance with its position in the head, so as to define a particular shape of the group of the free ends of the tufts that will touch the teeth during use of the toothbrush.

Such a shape is generally different for each toothbrush and is prepared so as to improve the contact of the bristles with the teeth surface and accordingly, to improve the brushing action and removing of the impurities by the toothbrush.

The brushing action of a conventional toothbrush is in fact difficult, in particular in areas which are more difficult to reach, such as the inside of the dental arch and the interstices between the adjacent teeth. In fact, it is known that the best cleaning result is obtained when the bristles act on the tooth enamel with their free ends and with a limited pressure on the tooth. On the other hand, in the areas which are more difficult to reach, the bristles bend and act on the tooth with their lateral surface, or they cannot touch it at all. This reduces substantially the toothbrush effectiveness and consequently, does not allow optimal results to be obtained in terms of dental hygiene.

In order to obviate the above described drawback, a solution has been developed that includes retractable bristle tufts. In other words, such tufts are mounted slidingly in the respective holes and are subjected to the action of elastic means that allows them to retract partially, due to the pressure against the tooth surface.

By way of example only, the documents JP5305008A (Takagi Yoshiki), US 4,633,542 (Travel Bernard) and US 3,082,457 (Lucibello Florio) disclose as many technical solutions for a toothbrush with retractable bristles, in which the elastic means, acting on the bristle tufts, is formed by a membrane which extends substantially along the whole length of the bristles. Such a membrane is situated on the rear face of the head or on the front face, from which the tufts extend.

The above described technical solutions present considerable drawbacks and therefore, they have not been commercially successful. First of all, the presence of a single elastic membrane that acts on all the bristle tufts allows a rather limited axial range of motion thereof, and anyway, the range of motion of a tuft depends on the position of the adjacent tufts. This does not allow a toothbrush that implements such solution to reach in optimal way all the areas to be brushed.

Secondly, a hollow space is inevitably created between the membrane and the surface of the head, in which space residual toothpaste or material resulting from the teeth cleaning action can gather. This creates obvious hygiene problems, first of all if the toothbrush is used for a long time.

The document US2010017989 (Kraemer) describes a different technical solution for a toothbrush with retractable bristles. In the aforesaid document, an elastically acting device is associated to each tuft of bristles, the device comprising a circular frame, fastened to the head surface in correspondence to the edge of the hole that receives the same tuft. The terminal portion of the latter is connected to the circular frame by means of three elastic helical bars, that allow its minimum axial sliding and a small rotation about the axis of the tuft.

The technical solution described in the patent application of Kraemer, besides the drawback already found in other former analyzed solutions, that is the limited axial range of motion, has other drawbacks, resulting from the manufacturing and assembly complexity of many elastic devices and from the inevitable high final production cost.

Technical Problem

It is an object of the present invention to propose a toothbrush head, provided with elastically retractable bristles with a wide range of motion, capable of reaching easily all the areas of the dental arch with the bristles in the optimal operative position.

Another object of the invention is to propose a toothbrush head, which does not have areas at risk of residues deposit, or in any case, in which such areas are easily accessible for a periodical maintenance.

A further object is to propose a toothbrush head, in which the previous objects are obtained in a simple, efficient and not expensive way.

Technical Solution

The above mentioned objects are wholly obtained in accordance with the contents of the claims, by a toothbrush head, which includes: a body, having a front face and a rear face; a plurality of housings, provided between the front face and rear face; a plurality of bristle tufts, mounted slidingly in axial direction in a corresponding housing and extending from the front face; elastic means, associated to the bristle tufts, so as to allow the latter to slide axially along their housings, toward the inside of the toothbrush head, by effect of a push action exerted on their outer end. In particular, the aforesaid elastic means comprises, for each of the bristles tufts, an elastic band, which is fastened to the bristles tuft at or near the opposite side thereof, and which acts through the body inside a corresponding seat.

Advantageous Effects

An advantage offered by the present invention with respect to the devices of prior art, results from the fact that the elastically retractable bristles have a very wide range of motion, until they retract completely into the body of the head, and therefore, they are capable of reaching easily all the areas of the dental arch, with the same bristles in the optimal operative position.

Another advantage of the invention is that it obtains a toothbrush head, which does not have areas at risk of residues deposit, or in any case, in which such areas are easily accessible for a periodical maintenance.

A further advantage derives from the fact that it obtains a toothbrush head, which has a simple construction, is efficient and not expensive.

Description of Drawings

The characteristics of the invention, as they will appear from the claims, are pointed out in the following detailed description, with reference to the enclosed drawings, in which:

- Figure 1 is a perspective view of a toothbrush head obtained in accordance with the present invention;

- Figure 2 is a schematic top view of a housing for a tuft of bristles and of a corresponding tuft of bristles, according to a first embodiment of the invention;

- Figure 3 is a section view of the housing of Figure 2 and of the corresponding tuft, taken along the section plane III-III;

- Figure 4 is a schematic top view of a housing and of the corresponding tuft of bristles, according to a second embodiment of the invention;

- Figure 5 is a top view of a pair of housings and of the corresponding tufts of bristles, according to a third embodiment of the invention;

- Figure 6 is a section view taken along the section plane VI-VI of Figure 5;

- Figure 7 is a top view of a pair of housings and of the corresponding tufts of bristles, according to a fourth embodiment of the invention;

- Figure 8 is a section view taken along the section plane VIII-VIII of Figure 7.

Best Mode

With reference to Figure 1, the reference numeral 100, indicates a toothbrush head as a whole, obtained according to the principles of the present invention. In particular, the above mentioned Figure illustrates, as a pure example, a manual toothbrush. However, it is to be understood that the technical solutions of the present invention can be applied in a wholly similar way to the toothbrushes of different type, for example electric pulsing-oscillating ones.

The illustrated head 100 includes a body 1, provided with a front face 2 and a rear face 3, substantially parallel to each other. The body 1 is made of a material having suitable mechanical characteristics, typically a known plastic material, and is fastened, or constructed integrally with a stem 4 belonging to the handle of the aforesaid toothbrush.

A plurality of housings 5, provided in the body 1, are formed in particular by through holes between the fore face 2 and rear face 3 of the same body 1, made perpendicular with respect to the above mentioned

faces

2,3.

In each housing 5, there is mounted a tuft of bristles 6 sliding axially, formed by a plurality of bristles closely tightened one to another in correspondence to an inner end 6b thereof, situated near the aforesaid rear face 3, and free at the outer end 6a. This latter end is the one aimed at coming in contact with the teeth during the brushing operation, together with the free ends of the other bristle tufts 6.

In the illustrated embodiment, the bristles are kept tightened one to another by means of a cap 50, at the base of which there is provided a stop 51, aimed at going in abutment against the edge of the housing 5, so as to prevent the tuft of bristles 6 from going out from the body 1 toward the front face 2 thereof. However, it is to be understood that other means can be likewise advantageously used to obtain the same object; for example, the bristles can be tightened with a drop of a gluing product, which, while hardening, acts also as a stop. For sake of explanation simplicity, these different realization modes are not illustrated, as immediately understood.

Elastic means 7 is associated to each bristle tuft 6, so as to allow the same tufts 6 to slide axially inside their housings 5, and consequently to retract toward the inside of the head, by effect of a push action exerted on their outer end 6a, and consequently, to return to the rest position, when this push action ceases. In the aforesaid rest position, illustrated in Figure 2, the stop 51 goes in abutment against the edge of the housing 5, thus keeping the tuft of bristles 6 in a wholly advanced position.

According to a first embodiment of the invention (see also Figures 2 and 3), the elastic means 7 is constituted by an elastic band 17, formed by a thin strip of material, such as natural or synthetic rubber, or other, having suitable mechanical characteristics and elastic constant, as well as a high extension capacity. In practice, but not exclusively, during the prototype phase, the material used for dental dams, that is the elastic protection membranes used in small dental surgeries, resulted particularly suitable. In any case, these are materials having quite common characteristics and easily available on the market. Also the section of the elastic band 17 can be chosen depending on the material, on the conformation of the housing 5 or the fastening requirements, remaining in any case within the scope of the invention. For example, polygonal, circular, elliptic, or relatively wide and thin sections can be used to form a strip.

The elastic band 17 is fastened at its end 17a, for example by means of gluing, to the stop 51 of the tuft of bristles 6, and at the other end 17b to the front face 2 of the body 1, near the edge of the housing 5, situated on the aforesaid front face 2. The length of the elastic band 17 is defined so as to keep the tuft of bristles 6 in the rest position with a minimum axial elastic action thereon.

The end 17b of the elastic band 17 can be fastened to the front face 2 of the body 1 by means of gluing or in other way of simple realization.

For example, a thickening can be made in correspondence to the same end 17b or an elongated element can be fastened thereto, perpendicularly to the axis of the elastic band 17, so as to secure it to the front face 2 in correspondence to the housing 5.

The elastic band 17 extends inside a seat 18 made in the body 1, that passes across it substantially from the front face 2 to the rear face 3. The aforesaid first embodiment (Figure 3) provides a seat 18a, formed by an axial groove 18a made in a wall of the housing 5.

The head 100 includes also a protection cap 9, preferably removable and fastened to the body 1 by means of

suitable joints

9a,9b, aimed at matching with

corresponding spaces

19a,19b made in the same body 1. The cap can be removed in order to allow the periodical cleaning operations of the inner part of the head 100, not accessible directly during the normal cleaning operations of the toothbrush. The cap 9 can be rigid or soft and elastic, so as to occupy less space.

The operation of the head 100 in accordance with the first embodiment of the invention is easily comprehensible. If the toothbrush is not used, all the bristle tufts 6 of the head 100 are kept in the rest position, hence completely extended, by the corresponding elastic bands 17.

When the toothbrush is used and is put on the user's dental arch with a moderate pressure, the outermost teeth areas exert a pressure on the bristle tufts 6, which they touch, making them retract toward the inside of the head 100, into the space included between the rear face 3 and cap 9.

Since each of the tufts of bristles 6 is provided with elastic means 7, that is wholly independent from the ones of the other tufts 6, it can easily retract even for its entire length, by virtue of high elasticity, while other adjacent tufts 6 could even not retract at all. This allows the group of bristle tufts 6 that form the head 100 to assume dynamically the shape of the dental arch they are brushing, however without bending due to the too high stresses and consequently, maintaining their optimal conformation. Likewise, in correspondence to the areas of the dental arch having more complex shape and being more difficult to reach, therefore, all the bristle tufts 6 keep the optimal contact with the teeth surface and contribute in the same way to their brushing and consequently to the cleaning thereof.

Mode for Invention

A second embodiment of the invention includes a seat 18b, formed by an oblique through hole, made between the front face 2 and the housing 5, near the rear face 3 of the body 1. As for the rest, the operation of the elastic band 1 in this second embodiment is identical to the operation of the first embodiment described previously.

A third embodiment, illustrated in Figures 5 and 6, includes elastic bands 27 associated to pairs of adjacent bristles tufts 6. An elastic band 27 is in fact fastened, at one of its ends, to the stop 51 of a tuft, and at the opposite end to the corresponding stop 51 of the other tuft of the pair. In this case, there is provided a seat 28, common for the respective pair of housings 5 that receive the bristle tufts 6, formed by an axial channel, in which there is the elastic band 27, common for the two tufts of bristles.

A cross bridge 29, provided near the axial channel 28, that opens into the front face 2, is fastened to the walls of the same channel 28 or made integral with the body 1. In this case, the elastic band 27 is arranged so as to pass over this bridge 29, so that the latter acts as abutment for the intermediate part of the same elastic band 27.

The operation of the head 100 according to the third embodiment of the invention is quite similar to that already described with reference to the first embodiment. In this case, the bigger length of the elastic band 27 makes it possible for both bristle tufts 6 of the pair to retract freely, against the elastic action of the same elastic band 27, substantially independent from each other, and anyway without any limitation of their maximum range of motion.

An advantage of this third embodiment results from the fact that it is not necessary to fix the elastic band 27 to the body 1 of the head 100.

Also a fourth embodiment of the invention, illustrated in Figures 7 and 8, includes an elastic band 37, fastened to the stops 51 of a pair of adjacent bristle tufts 6.

Seats 38 are made in the housings 5 which house the pair of bristle tufts 6, the seats 38 being formed by counter-facing axial grooves, inside which the above elastic band 37 passes, with its intermediate part resting on the portion of the front face 2 interposed between the two axial grooves 38.

The operation of the head 100 according to the aforesaid fourth embodiment of the invention is substantially identical to that already described with reference to the third embodiment of the invention.

It is understood that what above has been described as a pure and not limiting example. Therefore, possible modifications and variants of the invention are considered within the protective scope granted to the present technical solution, as described above and claimed below.

Claims

A toothbrush head, of the kind comprising: a body (1), having a front face (2) and a rear face (3), fastened to a stem (4) belonging to a toothbrush handle; a plurality of housings (5), provided in said body (1) between said front face (2) and rear face (3); a plurality of bristle tufts (6), each of which mounted slidable axially on a corresponding housing (5) and extending from said front face (2); elastic means (7), associated to said bristle tufts (6) so as to allow the same to axially slide along their housings (5), toward the inside of said toothbrush head (100), by effect of a push action exerted on their outer end (6a), and so as to force them to slide in the opposite direction when said push action ceases; said toothbrush head (100) being characterized in that said elastic means (7) comprises, for each of said bristles tuft (6), an elastic band (17,27,37), one end of which is fastened to said bristles tuft (6) at the opposite, inner side (6b) thereof, and which is fit to act through said body (1) inside a corresponding seat (18,28,38), said elastic band being moreover held at or near said front face (2) so as to exert its elastic return action.
A toothbrush head according to Claim 1, characterized in that said elastic band (17) is fastened, at one of its ends (17a), to a stop (51) made at the inner end (6b) of said bristles tuft (6), the opposite end (17b) of said elastic band (17) being fastened to said front face (2) of the same body (1).
A toothbrush head according to Claim 2, characterized in that the seat (18) of said elastic band (17) consists of an axial groove (18a) made in a side of said housing (5).
A toothbrush head according to Claim 2, characterized in that said seat (18) of said elastic band (17) consists of a through hole (18b) made between said front face (2) and said rear face (3) near said housing (5).
A toothbrush head according to Claim 1, characterized in that each of said elastic bands (27) acts on a pair of adjacent bristles tufts (5), the relative pairs of housings (5) communicating by means of an axial channel (28) fit to act as a seat of the corresponding elastic band (27), a cross bridge (29) being provided in said axial channel (28) near said front face (2), said elastic band (27) being fastened at its opposite ends to the corresponding ends of said adjacent bristles tufts (6), and extending from said tufts (6) over said cross bridge (29).
A toothbrush head according to Claim 1, characterized in that each of said elastic bands (37) acts on a pair of adjacent bristles tufts (5), corresponding counter-facing axial grooves (38) being made in the relative pairs of housings (5), and fit to act as seats for said elastic band (37), this latter being fastened at its opposite ends to the corresponding ends of said adjacent bristles tufts (6) and extending between said bristles tufts 6 through said axial grooves (38) and over said front face (2).
A toothbrush head according each one of Claims 1 to 6, characterized in that said elastic band (17,27,37) has a polygonal section.
A toothbrush head according each one of Claims 1 to 6, characterized in that said elastic band (17,27,37) has a circular or elliptical section.
A toothbrush head according each one of Claims 1 to 6, characterized in that said elastic band (17,27,37) is made as a thin strip of elastic material.
A toothbrush head according to Claim 1, characterized in that it moreover comprises a removable cap (9), fit to cover the rear portion of said body (1) at said rear face (3) thereof.