Tootbrush

The invention relates to a toothbrush with a handle, with a head which has a base end facing the handle and a tip end facing away from the base end and which is connected to the handle at the base end, the head and the handle being arranged along a longitudinal axis of the toothbrush and the head has a bristle surface from which bristles protrude and an opposite surface and there are edge surfaces between the bristle surface and the opposite surface, between which the width direction is defined.

Toothbrushes with a flexible bonded area in their head are known. In WO 92/17093 A, for example, a toothbrush is disclosed in which the head is divided into two or more sections which are flexibly and elastically connected to one another and / or to the handle of the toothbrush. In one embodiment, this known toothbrush has a head with grooves in the side opposite the bristle side, these grooves being filled with an elastomeric material in order to modulate the flexibility. In the disclosed embodiment, the grooves are arranged evenly distributed over the back of the head or around the longitudinal center point of the head in order to enable the entire head to be adapted to the curved shape of the teeth. WO 96/02165 A discloses similar toothbrushes with flexible heads in which the bristle ends have a generally concave profile. DE 87 05 474 U shows a toothbrush in which a tip area of ​​the head is articulated to a base area of ​​the head and an operating button on the handle enables the tip area to be bent in relation to the base area.

It is an object of this invention to provide a toothbrush of the type mentioned in the opening paragraph, in which efficient flexibility of the head, particularly near the tip of the head away from the handle, is achieved in order to properly clean tooth surfaces facing the rear part of the oral cavity with the toothbrush to be able to.

The toothbrush according to the invention of the type mentioned at the beginning is characterized in that the head is subdivided lengthwise into segments made of plastic material, each extending over the entire width of the head to the edge surfaces, whereby in the longitudinal direction adjacent segments are resiliently connected via a connecting area are that one opening

AT 003 615 U2 between the segments, which extends over the entire width of the head to the edge surfaces and is only bridged by an elastomeric material.

With such a design of the toothbrush, good flexibility of the head of the toothbrush is obtained, the connection of the head segments taking place in a way that enables the segments to pivot elastically relative to one another while brushing the teeth. The elastomer connection provided in the connection area between the segments enables the segments to be bent or pivoted during use about a bending or pivoting axis which runs generally transversely to the longitudinal axis of the toothbrush, with the bristles in the front segment being able to lean backwards, ie the free ends of the bristles in this segment can pivot in the direction of the handle, which assists the bristles in cleaning the tooth surfaces facing the rear part of the oral cavity. The flexible connection also helps avoid excessive frictional pressure when brushing your teeth.

Typically, the head of the toothbrush is connected to the handle of the toothbrush by a neck area between the base of the toothbrush head and the portion of the handle that is held in use.

The head segments can be essentially stiff, ie during the process of brushing the teeth they do not bend significantly beyond the usual limits of the bending of a toothbrush head made of plastic material.

The connection area is preferably in the longitudinal half of the head remote from the base end of the head, for example at least 60%, in particular at least 75%, of the distance between the base end and the tip end of the head.

The front segment can have various shapes, adapted to the shape of the top of the head, e.g. circular, triangular (including pointed arch), rectangular, oblong, diamond-shaped, etc.

In the unloaded state, ie when the toothbrush is not in use, the bristle surfaces of the segments of the toothbrush according to the invention can be essentially coplanar, that is to say that the angle between the segments is essentially 180 °. However, angles of less than 180 °, e.g. 150 ° -179 °, can also be used.

AT 003 615 U2 expediently 155 ° -170 ° can be provided. A suitable angle is such that the free ends of the bristles at the adjacent ends of the segments are in close proximity to one another, for example touch one another.

The connection area between the segments has an opening, a space or gap which is bridged with the aid of elastomeric material, it being possible under certain circumstances to contain one or more thin connections made of flexible and elastic plastic material. In this configuration, the head is effectively in segments that are connected by such articulations. The gap between the segments contains a complete or partial filling of an elastomeric material, which is preferably connected to the segments on opposite sides of the opening or the gap in order to hold the segments together.

The above openings may include a slot, gap or cutout across the width of the head separating the segments from one another. Such an opening can be open on the bristle surface of the head and / or on the opposite surface of the head and pass completely through the head. These openings or gaps can have various shapes, for example those of straight slots in the width direction. The openings can also be curved or angled, for example in the general shape of a C, U or V. With such a design, the convex bulge of the U or C or the tip of the V can either be in the direction of the handle or in the direction of the tip of the Head away from the handle. Furthermore, such an opening or such a gap can be narrow at the edges of the head and become wider towards the center of the head.

The opening may also include a groove as deep as part of the thickness of the head so that the remaining plastic material at the bottom of the groove forms a thin joint of plastic material. The groove can then be filled with the elastomeric material to form the joint area.

Preferably, however, the opening extends completely through the thickness of the head at least in some places, with bridges made of head material being left in place if necessary.

The opening may extend in the width direction to the edge surfaces of the toothbrush head and that is located therein

AT 003 615 U2 borne elastomeric material can continue around at least one of the segments of the head to form an elastomeric buffer around the toothbrush head to reduce impacts of the toothbrush head against the user's gums, as well as to gently massage the gums . In particular, an elastomeric material can be provided around the front segment of the head in order to form an elastomeric buffer in a manner known per se, such as, for example in FR 442832 A and DE 36 28 722 A described.

The outer surface of the elastomeric material in the opening can have a corrugated surface which can further help control the flexibility of the joint area.

In one embodiment of the toothbrush according to the invention, the head is designed in such a way that its front segment swivels or elastically backwards relative to the rear segment, which is closer to the handle, about a bending axis that crosses the head in the connection area, while brushing the teeth. is bendable. The bending axis can cross the head in the opening or at the edge of the opening.

On the other hand, it can also be provided that the front segment is elastically pivotable relative to the rear segment about a pivot axis running in the width direction which crosses the front segment between the tip end and the base end.

This design results in the front segment executing a back and forth movement when pivoting, with the part of the front segment located in the direction of the tip of the head pivoting towards the bristles, away from the plane between the Bristle face and the opposite face of the head, whereas the part of the front segment towards the base end of the head pivots opposite to the direction of the bristles, away from the plane, which lies between the bristle surface and the opposite surface of the head.

Such pivoting can be achieved, for example, with a design of the head in which the tip end of the rear segment is in the form of two legs which partially enclose a part of the front segment which extends in the base direction between them. For example, the tip end of the posterior segment may be in the form of a two-pronged, fork-like

AT 003 615 U2

Frame present, with part of the front segment between the two prongs of the fork. However, it is also conceivable that the base end of the front segment has the shape of two legs which surround a part of the rear segment which extends between them in the direction of the tip.

For example, the front segment may be generally in the shape of a C, U, or V, with the legs toward the rear segment, or it may be shaped like a Y, with the upper legs of the Y toward the rear segment. The part of the rear segment which extends in the direction of the tip can lie between these legs.

The elastomeric material can be an elastomeric material such as is commonly used in two-component toothbrushes, for example that described in EP 0336641 A, which can be bonded to plastic materials which are used for the manufacture of toothbrush handles. Such an elastomeric material can be injected into the toothbrush mold shortly after the plastic material parts of the toothbrush are injection molded so that the hot plastic material fuses and bonds to the elastomeric material. This is a known method per se.

In the rear segment, the bristles can be arranged in separate, generally circular cross-sectional tufts in patterns that are well known in toothbrushes, for example in rows in the width or length direction at generally conventional intervals. When melted down, the bristles can additionally or alternatively be arranged in mats with a cross-section which can be circular or other than circular.

In the front segment, the bristles can be arranged in separate, generally circular cross-sectional tufts, or, if they are melted down, they can additionally or alternatively be arranged in mats with a cross-section which can be circular or other than circular. In the anterior segment, it is preferred to have the tufts of bristles either (i) in a pattern of separate tufts arranged in a generally circular or polygonal pattern, or (ii) in a single tuft of generally circular cross-section at right angles to the bristle face, or ( iii) in a tuft of generally C- or V-shaped cross-section at right angles to the bristle face

AT 003 615 U2, wherein at least one of the legs of the C or U is aligned generally parallel to the longitudinal axis of the toothbrush and the rounded arc of the C or U points to the end of the bristle surface remote from the handle.

The ends of the bristles remote from the bristle surface can be essentially coplanar. Preferably, however, the ends run undulating around a plane in order to adapt the ends of the bristles to the undulating profile of the teeth; the bristle ends can also be in the form of battlements to facilitate cleaning of the interdental spaces. Such undulating bristle surfaces are known. In addition or as an alternative to this, the ends of the bristles that are remote from the bristle surface can lie in different planes in the segments. For example, the plane of the bristle ends in the front segment may slope upward, away from the bristle face, in a direction away from the handle. This can be achieved, for example, if the bristle surface of the front segment forms an angle of less than 180 ° with the bristle surface of the rear segment.

The handle can have a generally customary construction and can, for example, have a folded, flexible area and gripping surfaces made of elastomeric material, as is shown in EP 0336641 A, for example. Elastomeric gripping surfaces may alternatively or additionally be provided on other parts of the toothbrush handle, as is convenient.

The toothbrush according to the invention can be produced by generally conventional injection molding techniques, for example by first producing a skeleton of plastic material by injection molding, then introducing elastomer in a subsequent injection molding step, the elastomer being injected as hot fluid and bonding with the plastic material. Such techniques and suitable plastic and elastomer materials are known per se. The elastomeric material can then be injected using the same injection step that is used to inject the elastomeric gripping surfaces, and these various regions of elastomeric material can be interconnected by mold channels in a known manner.

If the bristle surfaces of the segments enclose an angle of less than 180 ° with one another, the connecting area both structural elements made of plastic material and the

AT 003 615 U2 has elastomeric material, the toothbrush is preferably produced in such a way that the plastic material skeleton is first produced by injection molding, the bristle surface being essentially flat; then the front segment is bent at the desired angle to the rear segment, and then the elastomer is injected into the connection area.

The bristles can also be of conventional design and made of conventional materials, and they can be fastened in the bristle surface by well known techniques, for example by small metal clips around the ends of the bristles to be fastened in the head, which are then inserted into recesses in the Bristle surface are wedged. Alternatively, again using known techniques, the bristles can be fused into the head material.

The invention will now be explained by way of example with reference to the drawing, in which FIGS. 1 to 36 show various plan, side and perspective views of toothbrush heads according to the invention as well as views without the elastomeric material, whereby the underlying construction of the head becomes visible.

1 to 4 show a toothbrush in which a front segment is designed so that it is elastic about a widthwise bending axis that crosses the head at the edge of the front segment facing a rear segment while brushing the teeth deflects relative to the rear segment.

This toothbrush contains a handle 1 with a head 2 which is integrally connected to the handle 1 at the base end 3 of the head 2, the head 2 and the handle 1 being arranged along a longitudinal axis AA of the toothbrush and the head 2 having bristles 4, which extend from a bristle surface 5 of the head 2 in a general bristle direction B.

The head 2 consists of two segments. A substantially rigid rear segment 6, which is integral with the handle 1, extends from the base end 3 of the head 2 to a location in the longitudinal half of the head 2 remote from the base 3. A front segment 7 extends from the outermost tip 8 of the head 2 to the rear segment 6. Both segments 6, 7 have bristles 4.

The segments 6, 7 are connected to one another in a flexible and elastic manner via a flexible connecting area which has an opening

AT 003 615 U2 in the head material 2 between the segments 6, 7. The opening 9 has the shape of a groove which is open on the bristle surface 5 of the head 2 and extends transversely over the entire width of the head 2. The groove 9 contains an elastic elastomeric material 10. The flexible connection between the segments 6, 7 is therefore obtained by the elastomeric material 10 together with the thinner plastic material at the base of the groove 9. The flexible connection enables the front segment 7 to bend elastically backwards relative to the rear segment 6 towards the handle 1 while brushing the teeth.

The front segment 7 is essentially circular and is delimited by the curved circumference of the tip 8 of the head 2 over part of its circumference and by a curved edge of the opening 9 over that part of the circumference of the front segment 7 which faces the rear segment 6 . The opposite edge of the opening 9, on the side first of the base 3, extends just over the width of the head 2, and the front segment 7 can pivot about the axis CC, which the head 2 in the opening 9 between the segments 6, 7 traverses so that the tip end 8 moves in the bristle direction B.

In the front segment 7 the bristles 4 are arranged in a generally polygonal pattern of tufts which includes a central tuft surrounded by a regular hexagonal pattern of tufts which are symmetrically arranged so that equal numbers of tufts, i.e. three of the surrounding tufts, are arranged on each side of the longitudinal axis AA of the toothbrush.

As can be seen more clearly in FIGS. 3 and 4, which show the head 2 without the elastomeric material 10 in the groove 9, the opening 9 is in the form of a groove which extends partially through the thickness of the head 2.

5 to 8 show an embodiment of the head 2 of a toothbrush in outline and elevation, the front segment 7 being designed so that when brushing the teeth it bends elastically in relation to the rear segment 6 about a pivot axis CC running in the width direction which crosses the head 2 at that edge of the front segment 7 which faces the rear segment 6.

7 and 8, the head 2 is shown without elastomeric material. The parts corresponding to those in Figs. 1 to 4,

AT 003 615 U2 are numbered accordingly. The front segment 7 has a generally triangular shape. The opening 9 is in the form of a rectilinear slot which extends widthwise through the head 2 of the toothbrush and entirely across its thickness, but includes thin integral bridges 11. The front segment 7 is able to bend about the axis CC passing through the head 2 in the opening 9.

The elastomeric material 10 extends around the tip 8 of the head 2 to form an outer buffer around the tip 8 of the head 2.

9, 10 and 11 show a toothbrush in which the front segment 7 is constructed in such a way that, when brushing the teeth, it swivels elastically in relation to the rear segment 6 about a joint axis running in the width direction, which the front segment 7 at one point crosses between the tip end 8 and the base end. In Fig. 11 the toothbrush head is shown without the elastomeric material. Parts that correspond to Figures 1 to 8 are numbered accordingly.

The head 2 consists of two segments. A substantially rigid rear segment 6, which is integral with the handle 1, extends from the base end 3 of the head 2 to a point in the longitudinal half of the head 2 remote from the base end 3. A front segment 7 extends from the extreme tip 8 of the Head 2 to the rear segment 6. Both the rear segment 6 and the front segment 7 have bristles 4.

The front segment 7 is flexibly and elastically connected to the rear segment 6 by a flexible connection which includes an opening 9 in the head 2 between the front segment 7 and the rear segment 6. The opening 9 contains a resilient elastomeric material 10 which extends around the tip end 8 of the front segment 7 to form a buffer. The rear segment 6 extends in one piece in the direction of the tip in the form of two legs which form a two-pronged fork which partially surrounds the front segment 7, which lies between the legs. The opening 9 partially surrounds the front segment 7 both on the side facing the rear segment 6 and on part of the longitudinal sides of the front segment 7, for example as a generally crescent-shaped opening.

The opening 9 has the shape of a slot that extends over the

AT 003 615 U2 extends the entire thickness of the head 2 of the toothbrush, but includes thin integral bridges 11, which are shown in Fig. 11, and which are provided at positions on the two longitudinal sides of the front segment which are aligned with one another in the width direction, and Provide pivot points about which the front segment 7 can pivot about the axis CC, which is shown in FIG. 11, as shown by the arrows in FIG. 9.

In FIGS. 12 to 14, another head 2 of a toothbrush is shown in which the front segment 7 is designed so that when brushing the teeth it is about a transverse axis CC (see FIG. 14), which the front segment 7 at one point crosses between the tip end 8 and the base end, elastically pivots with respect to the rear segment 6. In Fig. 14 the head 2 is shown without the elastomeric material. Parts that correspond to Figures 1 through 11 are numbered accordingly.

The head 2 consists of two segments. A substantially rigid rear segment 6, which is integral with the handle 1, extends from the base end 3 of the head 2 to a point in the longitudinal half of the head 2 remote from the base end 3. A front segment 7 extends from the extreme tip 8 of the Head 2 to the rear segment 6. Both segments 6, 7 have bristles 4.

The front segment 7 is flexibly and elastically connected to the rear segment 6 via a flexible connection which has an opening 9 in the head 2 between the front segment 7 and the rear segment 6. The opening 9 is open on the bristle surface 5 of the head 2 and extends over the entire width of the head 2 and through the entire thickness, but leaves thin integral bridges 11, which are shown in FIG. 14th are shown and which are provided at locations that are aligned with one another in the width direction. The opening 9 contains a resilient elastomeric material 10 which continues around the tip end of the front segment 7 to form a buffer. In plan view, the opening 9 has essentially the shape of a V, the tip of which points towards the tip of the head 2.

The base end of the front segment 7 is in the form of two legs which partially surround the tip end of the rear segment 6, which extends in one piece in the direction of the tip 8. The front segment 7 is therefore generally in the shape of a Y, with the tip end of the rear segment 6 between the legs 11

AT 003 615 U2 none of the Y is located.

The front segment 7 can pivot about the axis CC, about the pivot points provided by the bridges 11, so that when the tip end 8 of the front segment 7 moves in the direction of the bristle direction B, the base end of the front segment 7 moves downwards in moves in the opposite direction as indicated by the arrows in Fig. 12, that is, in a reciprocating manner.

Figures 15, 16 and 17 show a toothbrush with corresponding parts numbered accordingly. The bristles 4 are in the form of rectangular or polygonal mats, but could also be round tufts. In the toothbrush of Figures 15, 16 and 17, the opening 9 extends completely through the thickness of the head. An elastomeric material 10 completely fills the opening 9 and is connected to the opposite edges of the rear segment 6 and the front segment 7 in order to hold the two segments 6, 7 together elastically. FIG. 17 shows the bending of the front segment 7 when brushing the teeth in order to clean the surfaces of teeth 12 facing backwards.

18 to 21 show a variant of the toothbrushes described so far, with corresponding parts being numbered accordingly.

The bristles 4 are arranged in mats of a generally rectangular shape in the rear segment 6 and are adapted to the shape of the front segment 7, but could just as well be round tufts. The base end of the generally V-shaped front segment 7 is in the form of two legs which partially surround a part 13 of the rear segment 6 which extends towards the tip between them, with an opening 9 extending between the front segment 7 and the rear segment 6, more precisely between the legs and part 13; the opening 9 in turn contains an elastomeric material 10 which completely fills the opening 9 and is connected to the opposite edges of the segments 6, 7 in order to hold the segments 6, 7 together elastically. The elastomeric material 10 further extends along the outer edge 14 of the joint area to aid in massaging the gums and to protect the gums from impact with the toothbrush. When used as shown in Fig. 17th is shown, can

AT 003 615 U2 bend the front segment 7 relative to the rear segment 6 in order to adapt to the teeth 12, as shown in FIG. 20.

22 to 25 show a further variant of the toothbrush, with corresponding parts being numbered accordingly.

The bristles 4 are present in the rear segment 6 in mats of a generally rectangular shape and are adapted to the shape of the front segment 7; here too, of course, round tufts could be present. The base end of the generally V-shaped front segment 7 has two legs between which a part 13 of the rear segment 6 is received, which extends towards the tip 8 between them, with an opening 9 between the front segment 7 and the rear segment 6, which extends between the legs and the part 13 and which contains an elastomeric material 10. The elastomeric material 10 completely fills the opening 9 and is connected to the opposite edges of the segments 6,7 in order to hold these segments 6,7 together elastically so that the front segment 7 can pivot about the axis CC in use. This pivoting can be steered by the provision of plastic bridges (not shown) between the rear segment 6 and the front segment 7, aligned with the axis CC. In use, the front segment 7 can pivot about the axis CC with respect to the rear segment 6 to conform to the teeth, as shown in Figs.

26 to 29 show a toothbrush in which the front segment 7 pivots elastically with respect to the rear segment 6 about a transverse axis CC when brushing the teeth, which axis crosses the front segment 7 at a point between the tip end and the base end. Corresponding parts are again provided with corresponding reference numbers.

The head 2 again has a substantially rigid rear segment 6 which is integral with the handle 1 and extends from the base end 3 of the head 2 to a point in the longitudinal half of the head 2 remote from the base end 3 of the head 2. A front segment 7 extends from the outermost tip 8 of the head 2 to the rear segment 6. Both segments 6, 7 carry bristles 4.

The front segment 7 is flexibly and elastically connected to the rear segment 6, this connection in turn being a

AT 003 615 U2

Has opening 9 in the head material 2 between the segments 6,7. This opening 9 has the shape of a groove and is open on the bristle surface 5 and the opposite surface of the head 2. The groove 9 contains a resilient elastomeric material 10. The rear segment 6 extends in one piece towards the tip in the form of two legs which form a two-pronged fork which partially surrounds a part 15 of the front segment 7 which extends to the rear segment 6 and lies between the legs.

The elastomeric material 10 completely fills the opening 9 and is connected to the opposite edges of the rear segment 6 and the front segment 7 in order to hold the segments 6, 7 together elastically so that the front segment 7 swings about the axis CC in use can. This pivoting can be steered by the provision of plastic bridges (not shown) between the rear segment 6 and the front segment 7, aligned with the axis CC, in order to achieve an adaptation to the shape of the teeth when brushing the teeth.

30 to 32 are top and side views of an alternative embodiment of the head 2, in which the front segment 7 is elastically deflected relative to the rear segment 6 about a transverse axis CC when brushing the teeth.

FIGS. 30 and 31 show the head 2 without elastomeric material. Parts corresponding to those in FIGS. 1 to 4 have been given corresponding reference numerals. The front segment 7 is generally triangular with a rounded tip. A connection area is provided by an opening 16 between the segments 6, 7, which is bridged in one piece with the material of the head 2 by two strips 17 of plastic material, the strips 17 being thinner than the thickness of the head 2 and being between the two segments 6.7 extend. Viewed in the direction of thickness, the strips 17 are closer to the bristle surface 5 than to the rear of the head 2. The bristle surfaces 5 of the two segments 6, 7 are equipped with blind holes 18 for the insertion of bristles 4. As shown in Fig. 30, the holes 18 in the front segment 7 are arranged such that the bristles 4 are arranged in separate tufts 4A in a generally circular or polygonal pattern around a central tuft 4B.

According to Fig. 31, a skeleton was made only from the plastic material parts of the head 2 by injection molding, wherein

AT 003 615 U2, the bristle surface 5 is essentially flat.

As shown in FIG. 32, the skeleton thus formed was bent about the axis CC so that an obtuse angle of approximately 165 ° is formed between the bristle surface 5 of the front segment 7 and that of the rear segment 6. An elastomeric material 10 has been injected into the opening 16 while the head 2 was in the flexed condition and has been bonded to the sides of the opening 16 and the strips 17, filling the opening 16 and covering the strips 17. As a result, the toothbrush head 2 is held in its bent state, and the front segment 7 is connected to the rear segment 6 in a flexible and elastic manner.

The bristles 4 have been inserted by a conventional method, and the angle between the bristle surface 5 of the front segment 7 and that of the rear segment 6 is such that the free ends of the bristles 4 on the handle side of the front segment 7 are close to the free ends of the There are bristles 4 on the tip side of the rear segment 6. As in Fig. 32 As shown, the plane of the ends of the bristles 4 in the front segment 7 slopes upwards from the bristle surface 5 of the rear segment 6 in the direction away from the handle 1.

The elastomeric material 10 extends around the tip 8 of the head 2 to form an outer buffer 19 around the tip 8 of the head 2. For this purpose, a molding groove 19A is provided in the outer surface of the front segment 7.

33 to 36 show top and side views of yet another head 2 of a toothbrush, in which the front segment 7 is elastically deflected when brushing the teeth relative to the rear segment 6 about a transverse axis CC.

In Fig. 33 and 34 the head 2 is without elastomeric material ♦

shown. Parts corresponding to those in FIGS. 1 to 4 have been given corresponding reference numerals. The front segment 7 is generally triangular with a rounded tip. A connection area is provided through an opening 20 between the front segment 7 and the rear segment 6, the opening 20 being bridged by two strips 21 integral with the plastic material of the head 2; these strips 21 are thinner than the thickness of the head 2 and extend between the front segment 7 and the rear segment 6. The opening 20 has 15 on top

AT 003 615 U2 generally has the shape of a V on the bristle surface 5, the tip of the V pointing towards the handle 1. Viewed in the direction of thickness, the strips 21 are closer to the bristle surface 5 than to the rear of the head 2. The strips 21 are not planar, but rather are bent into and out of the plane of the rear segment 6 and the front segment 7.

The bristle surfaces 5 of the two segments 6, 7 are equipped with blind holes 22 for inserting bristles 4. As in Fig.

1-36, the holes 22 in the front segment 7 are arranged so that the bristles 4 are arranged in separate tufts in a generally circular or polygonal pattern around a central tuft.

As shown in FIGS. 33 and 36, a skeleton consisting only of the plastic material parts of the head 2 was produced by injection molding, the bristle surface 5 being pivoted about the axis CC so that an obtuse angle of about 165 ° between the Bristle surface 5 of the front segment 7 and that of the rear segment 6 is formed.

An elastomeric material 10 has been injected into the opening 20 while the head 2 was in a flexed condition and has been bonded to the sides of the opening 20 and the strips 21, filling the opening 20 and covering the strips 21. As a result, the head 2 is held in its bent state, and the front segment 7 is connected to the rear segment 6 in a flexible and elastic manner. The outside of the elastomeric material 10 has a corrugated surface, as shown in Fig. 36 can be seen.

The bristles 4 shown in FIG. 36 have been inserted by a conventional method, and the angle between the bristle surface 5 of the front segment 7 and that of the rear segment 6 is such that the free ends of the bristles 4 are on the handle side of the front segment 7 near the free ends of the bristles 4 on the tip side of the rear segment 6. As in Fig. 36 As shown, the plane of the ends of the bristles 4 on the front segment 7 slopes upwards from the bristle surface 5 of the rear segment 6 in the direction away from the handle 1.