EP1726237B1 - Brush and associated production method - Google Patents

Abstract

The brush has a grasp which is connected to a brush neck with a brush head. The head which is equipped with bristles (14) and has at their attachment-lateral ends a swollen part (16) connecting to a base (2). The swollen part is arranged between grasp, neck and head. The base has a brush head upper layer (10) and a brush head back layer (18). The brush head upper layer is towered, and functional elements (20) arranged at the brush head. The functional element is molded on to the brush head upper layer. An independent claim is included for a production method.

Description

The present invention relates to a brush, in particular toothbrush with a brush handle, which is connected via a brush neck with a brush head, which is equipped with bristle bundles, which are provided at their fastening side ends with a thickening, which between a brush handle, the brush neck and the brush head head formed base body and a rear side of this molded Bürstenkopfrückenschicht are arranged. The present invention further relates to a method for producing a brush, in particular a toothbrush, in which a basic body comprising a brush handle, a brush neck and a top layer of a brush body is produced by injection molding, bristle bundles are inserted through recesses recessed on the top layer and secured against the top layer, and On the back of the upper layer, including the attachment-side ends of the bristle bundles a Bürstenkoprückücken is molded.

A generic brush is, for example, from the date of the present applicant EP-0 623 298 known. In this prior art brush, a base body is formed as a plastic injection molded part with recesses recessed therein for receiving bristle bundles. Through these recesses bristle bundles are inserted, which are provided at its mounting end by melting with a thickening forming melt droplets. Thereafter, the bundles of bristles are secured by extension in the direction of the use-side top of the brush head. The brush head is finally completed by molding a plastic compound on the back of the brush head top layer, which is firmly bonded to the brush head during curing and which holds the mounting side ends of the bristle bundles between them and the upper brush head layer.

The upper brush head layer is formed in the known from this prior art brush as a one-piece component together with the brush neck and the brush handle, so that the previously known method for producing a low-cost and simply trained toothbrush, which has the advantages of an anchorless attachment of the bristle bundle brings the brush head with it. These advantages include in particular a relatively small thickness of the brush head, with regard to a use of the toothbrush in the relatively narrow mouth is significant. The upper brush head layer is accordingly made relatively thin, but thicker than a film and the dimensioning of the upper brush head layer is particularly in view of the fact that the bristle bundles can not be pulled out through the upper brush head layer in a conventional use of the brush.

From the DE 200 13 862 a brush is known in which the brush head consists of meandering intermeshing, extending at right angles to the bristle bundles brush head areas. The use-side surface of the brush head is formed by a film which forms a multiplicity of underside closed outlets for receiving in each case a bundle of bristles. On the back of this plastic film is a soft elastic molded plastic. This embodiment is intended to allow better pivotability of individual bristle bundles in the brush head. However, the method for producing such a brush head is relatively expensive. In particular, there is the problem that in the injection molding of the relatively thin-walled film plastic in the injection mold freezes early and hampers a complete mold filling. The relatively complicated injection mold leads to an increase in the manufacturing cost of the brush. In addition, the problem remains unclear how the bristle bundles can be securely anchored in the film, as the meandering film itself does not provide sufficient resistance to deformation acting on the bristle bundle extraction force and this lack not by the soft elastic molded on the back of the brush head soft elastic plastic is corrected.

From the DE 101 64 336 Finally, it is known to prevent bundles of bristles from being pulled out by forming a thickening on the back of a brush head. The known from this state of the art brush head, however, does not meet the hygienic requirements and remains in this regard behind from the EP-0 623 298 known solution proposal back.

Another, at least two-layer construction of the brush head is from the DE 102 21 716 known to the present applicant. In this prior art, the attachment-side ends of the bundles of bristles are received in a soft elastic plastic material, whereby the pull-out strength of the bristle bundles is impaired.

The present invention is based on the problem arising from the EP-0 623 298 to improve known brush in terms of their performance characteristics. Furthermore, the present invention is based on the problem of specifying a method for producing such a brush.

To solve the device-related problem, the present invention provides a brush having the features of claim 1. This differs from the generic brush in that the brush head top layer is arranged on the brush head, injection molded functional elements is surmounted that the functional element is formed by a ring which surrounds a single bundle of bristles and that individual rings are injected through a respective recess and by encapsulation the brush head top layer are connected. Through the rings, the guide length formed by the recess of the brush head top layer is extended for the bristle bundles and so also the Wiederaufrichtvermögen the bristle bundles and in particular the service life of the brush improves. Therefore, there is the possibility of forming the brush head top layer with a minimum thickness that can still be tolerated with regard to the pull-out strength, without having to forego the advantages of a sufficient guide length of the bristle bundles.

In addition, as functional elements in the context of the present invention, all elements are to be understood which increase the usefulness or improve the functionality of the brush. These functional elements include, in particular, soft-elastic functional elements which serve for the additional cleaning and / or massage of the teeth or of the gums. These include in particular the brush head superior massage fingers or pillows. As functional elements also the lateral edge of the plastic top layer superior coatings can be provided, which serve as impact protection for the regularly formed on grounds of a sufficient pullout strength of a hard plastic plastic top layer. Alternatively, the functional elements may also be parts of a joint. If provided by the functional elements cleaning or massage elements of the brush, this leads to a brush with increased usability. In technical functional elements, such as joints or joint parts, the brush has improved functionality.

The injection-molded functional elements according to the invention, which project beyond the brush head upper layer, can not be used together with other functional elements which do not necessarily have the brush head upper layer project beyond, be provided, in particular be formed in one piece. In this way, a different requirements sufficient brush can be produced in a simple manner, which has a sufficient flexibility, for example, in the neck area and also includes functional elements, such as massage or cleaning element in addition to conventional bristle bundles.

With a view to a good and simple attachment of the functional elements to the brush head top layer, these are preferably injection-molded onto the brush head top layer and thus materially connected to the main body.

With regard to a relatively simple embodiment of the brush according to the invention and accordingly in view of the cost of producing the brush, it is preferable to form the main body as a one-piece injection molded part with recesses for the functional elements recessed therein. The inclusion of functional elements in the recesses also improves the connection between the main body and the functional elements, which may be particularly advantageous in the formation of the functional elements of a flexible plastic in view of the sometimes poor adhesion properties of the soft elastic plastic to the component of the body.

Furthermore, in order to reduce the production costs and to simplify the production process, it is proposed according to a further preferred embodiment to form the functional elements and the brush-head back-layer in an identical manner. When spraying the Bürstenkoprückschicht so that at the same time the functional elements can be formed, leaving open the possibility to produce the brush in the two-component injection molding. Between the formation of the first and the formation of the second component, only the bristle bundles need to be introduced into corresponding bristle channels of the brush head top layer. The functional elements are preferably designed as cleaning elements extending substantially parallel to the bundles of bristles, for example in the form of massage fingers or wipers. The cleaning elements are characterized in particular by the fact that they are formed approximately with the same length as the bristle bundles and thus when cleaning the brush, for example when using the brush as a toothbrush in a mouth, substantially simultaneously with the bristle bundles are active in cleaning.

Moreover, according to a further preferred embodiment, the rings may be provided in combination with the abovementioned cleaning elements and may preferably project beyond the brush head top layer by 1/5 to 3/5 of their axial length on the top side. The other side of the rings preferably reaches at most up to the back of the brush head top layer. However, the rings can also terminate at a certain distance from this rear side in the brush head top layer and between the front end of the rings and the rear side, the material of the brush head top layer can have an up to the bristle bundles protruding to the bristle bundles with higher pull-out strength to the body to back up.

Of course, it is possible to combine the preferred embodiment with separate, surrounding the bristle bundles rings and the design with functional elements in the form of cleaning or massage elements that are injected through one of the recesses with each other. Here, first, the rings are molded together with the massage or cleaning elements on the brush head. Thereafter, the bristle bundles are passed through those recesses in which rings have been formed. Thereafter, the encapsulation of the Bürstenkopfrückenschicht to secure the attachment-side ends of the bristle bundles.

To solve the procedural problem, the present invention provides a manufacturing method for manufacturing a brush in which the aforementioned base body is produced by injection molding. By recesses which are recessed on the upper layer, a bundle of bristles is then introduced in each case. With a view to the fastest possible bristling of the base body, a perforated field plate is preferably first provided with Sorstenbündeln this, the hole pattern corresponds to the pattern of bristle bundles to be provided with recesses of the body. These bristle bundles are then, after the perforated field plate has been aligned with their holes in alignment with the corresponding recesses, transferred simultaneously into the recesses of the body. Only then is a thickening periodically formed at the attachment-side ends of the bundles of bristles, for example by an adhesive drop or a melt drop created by melting the ends. Now the bristle bundles are secured opposite the upper layer. Then, against the back of the topsheet, including the fastener-side ends of the bundles of bristles, a brush-head backsheet is molded. In addition to these conventional process steps the method according to the invention comprises a step in which the functional elements, which project the upper layer, are formed by injection molding and connected to the brush head. Furthermore, the inventive method comprises a step in which a plurality of functional elements are injected in the form of separate rings in individual recesses of the upper class. Alternatively, the functional elements designed in particular as separate rings can be formed together with the bristle bundles as a structural unit, which is connected as such to the base body.

However, the functional elements are preferably formed for the reasons already discussed above by molding the upper layer with a thermoplastic elastomer, preferably by spraying through selected recesses. When encapsulating all recesses can be injected. Alternatively, only predetermined recesses can be injected, in particular those which serve to receive bundles of bristles, whereas other recesses can be injected during encapsulation of the brush head back layer to form further functional elements, in particular in the form of cleaning elements.

An improved attachment of the functional elements to the upper layer is created according to a preferred development of the present invention, characterized in that the functional elements are formed with a voltage applied to the back of the upper layer and a plurality of functional elements functional element base as a one-piece functional element injection molded part. The functional element injection-molded part preferably forms the basis for all functional elements formed by encapsulation of the upper layer. This composite is connected with high security inextricably linked to the body.

A further procedural simplification results from the fact that the Bürstenkoprückschicht is injected as part of the functional element injection molded part. This functional element injection molded part then preferably forms the second and only further component forming the brush head.

For the reasons already presented in relation to the device-based solution of the invention, the base body is preferably produced as a one-piece injection-molded part, preferably of a hard component, wherein the through-cut recesses in the injection molding are recessed at the top layer. The main body can be known per se Have one or more encapsulation for changing the haptic properties of the brush handle or to form joints or elastic regions of the brush handle or the brush neck. These encapsulations are preferably formed when forming the functional elements on the brush head, wherein the at least one encapsulation is not necessarily formed, but preferably material identical to the functional elements, ie the encapsulation is performed with the same soft elastic plastic component.

As an alternative embodiment to a one-piece base body, it is proposed according to a development of the invention to first form the brush head top layer as a brush head unit together with the functional elements and to connect them to a handle unit comprising the brush neck and the brush handle. This procedure provides the advantage that the relatively easy to manufacture handle unit can be made separately from the relatively complex brush head unit. In addition, with identical head units differently shaped handle units can be provided so that varying brushes can be made to economic conditions. It has proved to be useful to connect the brush head unit by spraying the Bürstenkopfrückenschicht with the handle unit. Brush head unit and handle unit are here inserted into a common mold cavity and by spraying the Bürstenkopfrückenschicht the brush is completed as made of at least two parts component.

Figur 1

einen Grundkörper zur Herstellung eines Ausführungsbeispiels der vorliegenden Erfindung in einer Längsschnittansicht;

Figur 2

eine nicht erfindungsgemäße Zahnbürste

Figuren 3, 4

die Zwischenschritte zur Herstellung eines Ausführungsbeispiels der vorliegenden Erfindung in Längsschnittansicht; und

Figur 5

eines Ausführungsbeispiel in einer Längsschnittansicht.

Further details, advantages and features of the present invention will become apparent from the following description of an embodiment in conjunction with the drawings. In this show:

FIG. 1

a main body for producing an embodiment of the present invention in a longitudinal sectional view;

FIG. 2

a toothbrush not according to the invention

FIGS. 3, 4

the intermediate steps for producing an embodiment of the present invention in longitudinal sectional view; and

FIG. 5

an embodiment in a longitudinal sectional view.

In FIG. 1 FIG. 3 is a longitudinal sectional view of a hard thermoplastic body 2 constituting a brush handle 4, a brush neck 6, and a brush head 8. The brush head 8 comprises an integrally formed as part of the base body 2 upper layer 10, which is formed as a substantially flat, plate-shaped member having a plurality of recesses 12.

The recesses 12 are - like FIG. 2 can be seen - partially equipped with bristle bundles 14. These bristle bundles 14 have at their fastening-side end a thickening 16 formed by melting of the bristle bundles 14. This thickening projects beyond the recess 12 in the radial direction and thus secures the bundles of bristles 14 against being pulled out in the direction of the utilization-side upper side of the upper layer 10.

On the back of the upper layer 10 is in the finished toothbrush after FIG. 2 a brush head backsheet 18 made of a thermoplastic elastomer formed by overmolding the thermoplastic elastomer against the back side of the topsheet 10, as shown in FIG EP-0 623 298 is known. In addition, the brush head back layer 18 has cleaning elements 20 integrally formed on this layer 18, which extend substantially parallel to the bristle bundles 14 and are formed approximately at the same height, ie, length, above the upper side of the upper layer 10. The cleaning elements 20 may be rod-shaped with a round or rectangular cross section and with a diameter which corresponds approximately to the diameter of the bristle bundles, be formed. Alternatively, the cleaning elements 20 may extend over almost the entire width or length of the brush head 8.

For the production of in the Figures 1 and 2 Toothbrushes shown, the base body 2 is produced in a conventional manner by injection molding. Thereafter, the transfer of bristle bundles 14 takes place without thickening in selected recesses 12. Then, the thickenings 16 are formed by melting. The attachment-side ends of the bristle bundles 14 may be at a distance from the upper layer 10 may be provided and applied to the back of the body 2 after creating the thickening. The base body provided with bristle bundle is then inserted into a second injection mold, which has the upper side of the upper layer 10 surrounding mold cavities for the cleaning elements 20, but otherwise there preferably funnel-shaped recesses for receiving the bristle bundles. A thermoplastic elastomer is injected into the cavity, preferably between the injection mold and the back of the topsheet 10. Thereafter, substantially initially the brushhead backsheet 18 is formed. With increasing mold filling, the thermoplastic elastomer exits through the free recesses 12 and fills the mold cavities for the cleaning elements 10. In this mold filling the thickenings 16 of the bristle bundles 14 compress the remaining recesses 12 from. In this case, a one-piece functional element injection molded part 21 comprising the cleaning elements 20 and the brush head back part 18 is formed, the functional element base of which the cleaning elements 20 connect to one another at the bottom being formed by the back part 18. After the thermoplastic elastomer has cooled sufficiently, the finished brush is removed from the mold.

That in the FIGS. 3 to 5 embodiment shown has the same body as the previously discussed toothbrush. Identical features are accordingly marked with the same reference numerals. In the FIG. 5 shown finished brush has a plurality of rings 22 which over an axial length with its outer peripheral surface to the inner periphery of the recesses 12 fitting. The rings 20 are presently designed as cylindrical components with a round cross-sectional area. About half of the axial length of the rings 22 projects beyond the upper layer 10. The rings 22 are penetrated by the bristle bundles 14. The thickening 16 is located at the mouth of the rings 22. The attachment-side end side of the rings 22 is aligned with the back of the top layer 10. The brush head back layer 18 is made of a thermoplastic elastomer and, accordingly, allows a certain spring back of the bristle bundles 14 at excessive axial compressive stress of the bristle bundles.

In the production of the in the FIGS. 3 to 5 1, the base body 4 is first inserted into a further injection mold. This has in the recesses 14 projecting cylindrical pin, which together with the rest Formed walls of the tool halves form an annular gap whose outer peripheral surface is aligned with the outer peripheral surface of the recesses 12. Thermoplastic material is injected into these spaces. This may be a hard plastic or a soft elastic plastic. Preferably, 10 flow channels are formed on the back of the upper layer, through which at the back of the upper layer 10 molded melt can reach the individual recesses 14. The solidifying melt forms the rings 22. Thereafter, from the back of the topsheet 10, bristle bundles 14 are inserted and thickened in the manner described above with reference to the first embodiment. Thereafter, the back of the topsheet 10 is overmolded and the brushhead backsheet 18 is formed.

LIST OF REFERENCE NUMBERS

2

body

4

brush handle

6

brushneck

8th

brush head

10

top layer

12

recess

14

bristle bundles

16

thickening

18

Brush head back layer

20

cleaning element

21

Functional element injection-molded

22

ring

Claims (24)

1. A brush, in particular a toothbrush with a brush handle (4) which is joined by way of a brush neck (6) to a brush head (8) which is provided with a bundle of bristles (14) which are provided at the ends thereof towards the fastening with a thickened portion (16) which is arranged between an upper layer (10) of the brush head, formed by a base body (2) comprising the brush handle (4), the brush neck (6) and the brush head (8), and a rear layer (18) of the brush head injection-moulded onto the rear side of the upper layer (10),
   characterized in that
   injection-moulded functional elements (20, 22) arranged on the brush head (8) project beyond the upper layer of the brush head,
   the functional element is formed by a ring (22) which surrounds a single bundle of bristles (14), and individual rings (22) are injected through one recess (12) in each case and are joined to the upper layer (10) of the brush head by having injection moulding take place around them.
2. A brush according to claim 1, characterized in that the functional element (20, 22) is injection-moulded onto the upper layer (10) of the brush head.
3. A brush according to claim 1 or 2, characterized in that the base body (2) is designed in the form of a one-piece injection-moulding part with at least one recess (12) formed therein for the at least one functional element.
4. A brush according to any one of the preceding claims, characterized in that the functional element (20) and the rear layer (18) of the brush head consist of identical material.
5. A brush according to any one of the preceding claims, characterized in that the functional element comprises a cleaning element (20) which is formed in one piece with the rear layer (18) of the brush head and which extends substantially parallel to the bundles of bristles (14).
6. A brush according to any one of the preceding claims, characterized in that the rear layer (18) of the brush head and/or the at least one cleaning element (20, 22) is formed from a thermoplastic elastomer.
7. A brush according to any one of the preceding claims with a region of reduced cross-section which is provided in order to form a joint on the brush neck (6) and/or the brush head (8) and which is provided with a soft elastic covering, characterized in that the covering is formed in one piece with the rear layer of the brush head and/or the functional element.
8. A brush according to any one of the preceding claims, characterized in that the rear layer (18) of the brush head extends as far as the external peripheral face of the upper layer (10) of the brush head in order to form a soft elastic abutting edge.
9. A brush according to claim 5 or 6, characterized in that the at least one cleaning element (20) projects beyond the brush head (8) with substantially the same length as the bundles of bristles (14).
10. A brush according to any one of the preceding claims, characterized in that from 1/5 to 3/5 of the axial length of the rings (22) projects beyond the upper layer (18) of the brush head at the top.
11. A brush according to any one of the preceding claims, characterized in that the rings (22) extend as far as the rear side of the upper layer (18) of the brush head.
12. A brush according to any of claims 9 and 11, characterized in that a plurality of cleaning elements (20) and a plurality of rings (22) are provided, and the rear layer of the brush head is provided in the form of a layer formed separately from these functional elements (20, 22).
13. A brush according to claim 12, characterized in that the cleaning elements (20) and the rings (22) are joined to one another in an integral manner on the rear side of the upper layer of the brush head.
14. A method of producing a brush, in particular a toothbrush, in which a base body (2) comprising a brush handle (4), a brush neck (6) and an upper layer (10) of a brush head (8) is produced by injection moulding, bundles of bristles (14) are introduced through recesses (12) formed on the upper layer (10) and are secured with respect to the upper layer (10), and a rear layer (18) of the brush head is injected onto the rear side of the upper layer (10) whilst including the ends of the bundles of bristles (14) on the fastening side,
    characterized in that
    at least one functional element (20, 22) projecting beyond the upper layer (10) is formed in the course of the injection moulding and is joined to the brush head (8), and
    a plurality of functional elements in the form of separate rings (22) surrounding bundles of bristles (14) are injected into individual recesses (12) in the upper layer (10).
15. A method according to claim 14, characterized in that the at least one functional element (20, 22) is formed by injection-moulding a thermoplastic elastomer around the upper layer (10).
16. A method according to claim 14 or 15, characterized in that the at least one functional element (20, 22) is injected through one of the recesses (12).
17. A method according to any one of claims 14 to 16, characterized in that the functional elements (20, 22) are formed with a functional element base (18), situated on the rear side of the upper layer (10) and joining a plurality of functional elements (20, 22), as a one-piece functional-element injection-moulding part (21).
18. A method according to claim 17, characterized in that the rear layer (18) of the brush head is injected as part of the functional-element injection-moulding part.
19. A method according to any one of claims 14 to 18, characterized in that surrounding injection mouldings are formed during the formation of the functional elements (20, 22) on the brush handle (4) and/or the brush neck (6).
20. A method according to claim 19, characterized in that the functional elements (20, 22) and the surrounding injection mouldings are formed by the base body (2) having the same material injection-moulded around it.
21. A method according to any one of claims 14 to 20, characterized in that the upper layer (10) is formed together with the functional elements (20, 22) as a brush head unit which is joined to a handle unit comprising the brush neck (6) and the brush handle (4).
22. A method according to claim 21, characterized in that the brush head unit is joined to the handle unit by injection moulding the rear layer (18) of the brush head.
23. A method according to any one of claims 14 to 19, characterized in that the base body is formed as the base body (2) as a one-piece injection-moulding part from a hard component, and the recesses (12) are formed as continuous recesses (12) in the upper layer (10).
24. A method of producing a brush, in particular a toothbrush, in which a base body (2) comprising a brush handle (4), a brush neck (6) and an upper layer (10) of a brush head (8) is produced by injection moulding, bundles of bristles (14) are introduced through recesses (12) formed on the upper layer (10) and are secured with respect to the upper layer (10), and a rear layer (18) of the brush head is injected onto the rear side of the upper layer (10) whilst including the ends of the bundles of bristles (14) on the fastening side,
    characterized in that
    at least one functional element (20, 22) projecting beyond the upper layer (10) is formed in the course of the injection moulding and is joined to the brush head (8), and
    a plurality of functional elements designed in the form of separate rings (22) surrounding bundles of bristles (14) are formed as a structural unit together with the bundles of bristles (14) and the structural unit is joined to the base body (2).

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