MXPA99007783A - Toothbrush - Google Patents

Abstract

A toothbrush in which the head comprises a substantially rigid base region adjoining the toothbrush neck and extending from the base end of the head to a resilient flexible link situated between the base end and the tip end, and a tip region extending from the tip end of the head to the link region, both the base region andtip region being bristle bearing, the tip region being flexibly and resiliently linked at the link region to the base region, and between the base end of the head and the neck there is a resilient flexible link.

Description

TOOTHBRUSH This invention relates to toothbrushes, in particular toothbrushes having a region flexibly attached to their head. Dental brushes having regions that modify flexibility in their structure are known, for example WO 92/17092, EP 01613636, EP 0648448A, WO 97/24949 and WO 97/07707. Said regions that modify the flexibility generally comprise the formation of a mixed region of the rigid plastic material from which the toothbrush is made together with a soft flexible elastomeric material. It is thought that the optimum flexibility characteristics have not yet been achieved in such toothbrushes and it is an object of this invention to provide a toothbrush in which the flexibility of the head is further improved. among other things, to increase the ability of the toothbrush to clean the surfaces of the teeth facing the back of the mouth. According to this invention a toothbrush comprises a handle and a head, the head having a base end that Look towards the handle and a tip end far to the base end a neck region between the base end and the head and the handle, the head joining the neck region at the base end of the head, the head, the neck and the handle being arranged along a longitudinal toothbrush axis, the head having bristles extending from a bristle face of the head, characterized in that the head comprises a substantially rigid base region joining the neck of the toothbrush and extending from the end of the base of the head to a resilient flexible joint located between the base end and the tip end and a tip region extending from from the tip end of the head to the region of the junction both the region of the base and the region of the tip having bristles the tip region being flexibly and resiliently joined to the region of connection to the base region, and, Between the base end of the head and the neck there is a resilient flexible joint The handle of a toothbrush is the part of the toothbrush that is held by the user while brushing their teeth In many toothbrushes the neck is a good region visually defined between the part of the toothbrush that is held and the head, but bulls dental brushes the head emerges relatively imperceptibly in the handle In general the term 'neck' as used herein includes all such possibilities, and especially the part in that the toothbrush is immediately adjacent to the base end of the head The construction described before the toothbrush flexibly concentrates the head to the end of the tooth of the toothbrush and also provides a flexible connection between the base end of the head and the handle of the toothbrush. The junction of the tip region and the base region preferably are in a shape that allows the region of the The tip is bent or rotated resiliently relative to the base region during brushing. The joint provided in the junction region between the tip region and the base region allows the tip region to bend or twist during use around a point. bending or a pivot axis which is generally transverse to the axis of the longitudinal toothbrush so that the needles on the region of the tip can be tilted backwards, i.e., so that the free ends of the bristles in the region of the tip swing towards the handle, helping the bristles clean the surfaces of the teeth facing towards the back of the mouth This fold or pivotal axis can be in the plane of the face of the teeth The flexible connection provided by this invention between the region of the tip and the base region and between the head and the neck also helps to avoid excessive brushing pressure which is applied by brushing. The base region is substantially rigid., ie during the brushing operation of the teeth, the base region does not flex significantly beyond the usual bending limits of a brushing head of plastic material. The oase region can suitably comprise an integral block of material of plastic provided with receptacles in which bunches of the bristles are mounted. The union region is preferably in the longitudinal head of the head furthest from the base of the head. Suitably, the base region extends at least 50%, suitably at least 60%, for example at least 75% of the distance between the base end and the head and tip of the head. The tip region can also be substantially rigid, so that the tip region does not flex significantly by itself away from its fold or rotate relative to the base region. The tip region may suitably comprise an integral block of plastic material provided with receptacles in which the bunches of bristles are mounted. In its non-taut condition, that is, when it is not being used, the bristle face of the tip region and the base region of the toothbrush of this invention can be substantially coplanar. that is, substantially with an angle of 180 ° between them. Alternatively, the face of the regions of the bristles of the tip region may form an angle less than 180 ° with the face of the bristles of the base region, e.g., 150 ° -179 °. suitably 155 ° -170 ° In this last mentioned construction, the ends of the bristles on the base region may be in or about a plane and the bristle heads on the tip region may be on or around a plane and the two respective planes can be coplanar or have an angle v gr., less than 180 ° with one another, for example an angle corresponding to the angle between the surfaces of the bristles of the base region and the region of the tip. The union between the tip region and the base region in an embodiment of this invention comprises an opening, gap or groove in the plastic material of which the head is made, between the tip and base regions that are joined together. by means of one or more unions of flexible and resilient plastic material. Said joints may comprise thin loins, thin strips or a continuous thin membrane, made of a flexible and resilient plastic material which may be in the same plane as a substantially planar head or may be inclined or may be curved out of the plane. The plastic material may be of the same plastic material of the tip and base regions but which are flexible because they are thin, that is, the tip, the base and the bristles may be integrally molded. In another embodiment of this invention the junction between the tip region and the base region may comprise a mixed region having structural elements made of plastic material and an elastomeric material. For example, the mixed region may comprise an opening, gap or groove in the head material between the tip and base regions which are joined by means of a combination of thin loins, strips or a thin continuous membrane of a flexible plastic material. and resilient, v gr, integral with the head and also by an elastomeric material in the opening, gap or groove These ridges, thin strips or membranes may be a plane parallel to the plane of the face of the bristles of the tip region or The base region may or may be bent or curved or bent out of any parallel relationship with the planes. The mixed region may for example comprise a network structure, loose mesh, lattice, cellular or lattice structure of plastic material integral with the head material, with interstices containing the elastomeric material. Said mixed region for example may comprise one or more, for example two. strips of a plastic material integral with the material of the head, the strips being thinner than the thickness of the head and extending between the tip region and the base region, to join the opening, gap or groove between the region tip between the tip region and the base region, the opening, gap or slot also contain an elastomeric material, suitably attached to the sides of the gap and to the strips and suitably having separation or slot, optionally also warping above the surface of the surrounding plastic material of the head The plastic material portions in said mixed region may be thick enough to materially contribute to the flexibility and resilience of the bonding region, or alternatively they may be so thin that they contribute to flexibility and resilience of the union region and therefore can serve simply to retain the regions of tip and head before the elastomer is added. In another embodiment of this invention, the junction region between the tip region and the base region may comprise an opening, gap or groove in the head material between the tip and tip regions. base that are joined only by a complete or partial filling of an elastomeric material In this construction the head effectively in two regions with a gap between them containing the elastomer This elastomeric material is preferably attached to the tip region and the base region in a the opposite sides of the opening, gap or slot so as to hold together the tip region and the base region. The openings or separations mentioned above may comprise a channel, slot or cut across the width of the head, dividing the base region of the tip region This opening can be opened in the face of the bristles of the head and / or the opposite face of the head and p It can pass completely through the head. Such openings or grooves may have various shapes such as wide-path grooves. These may be wider, substantially straight, curved or angular, generally in the form of a "C" U or "V" In this construction the convex protrusion of the U 'or' C "the appendage of the V can point towards the handle or towards the tip of the head and away from the handle Alternatively said opening gap or slot can be narrow at the edges from the head and expand towards the center of the head or vice versa. Suitably for example the opening, gap or slot may comprise one or more channels, preferably one with a depth of part of the thickness of the head so that the plastic material and the bottom of the slot form a thin junction of the plastic material . The groove can then be filled completely or partially with elastomeric material to form a mixed region. Alternatively, the opening, gap or groove can pass, at least at least, completely through the thickness of the head, for example coming out of the joints of the head material crossing the opening, gap or groove between the places where the opening , separation or groove pass completely through the thickness of the head. Said opening, gap or groove may be filled completely or partially with elastomeric material to thereby form a mixed region. When the opening, gap or groove passes completely through the thickness of the head for its entire length they can be filled completely or partially with an elastomeric material. The opening, gap or slot can extend widthwise towards the sides of the head of the toothbrush and the elastomeric material therein to extend around the region of the tip and head and / or around the region of the base of the toothbrush. the head to form an elastomeric buffer around the head of the toothbrush to soften any impact of the head of the toothbrush with the user's gums and also for the soft massage to the gums Alternatively the elastomeric matepai can be provided around the region of the tip of the head to form an elastomeric buffer in a known way When the opening, separation or groove contains an elastomeric material the outer surface of this elastomeric material may have a corrugated surface which may further help to control the flexibility of the joining region. In one embodiment of the toothbrush of this invention, the head is constructed so that a tip region can be resiliently bent backwards relative to the base region, during the brushing of the teeth, around the wide part oriented on the axis crossing the head in the joining region. The bending axis through the head or at the edge of an opening, gap or groove as described above In said construction the opening, gap or groove may be shaped such that the longitudinally oriented fold axis crosses the toothbrush head completely between the opening, separation or groove When the joining region is a mixed region as described above the fold may prese Bending by flexing the plastic material parts described above or by flexing at the point where said part meets the edge of the opening gap or groove. Such construction may cause the entire tip region to bend in the direction of the bristles away. of the plane between the face of the bristles and the opposite face of the head, so that the region of the tip actually bends back towards the base region during the use of a toothbrush In an alternative embodiment of the toothbrush of this invention, the tip and / or joint region can be constructed and positioned so that the tip region can rotate resiliently relative to the base region during the brushing of the teeth about a pivotal axis oriented toward the tooth. width that crosses the region of the intermediate point between its tip end and its base end Said construction causes the pivoting of the tip region around of this intermediate axis along its length, ie occasion that the tip region has a "saw" action in which during the brushing part of the teeth from the region of the tip to the tip of the head rotates in the direction of the bristles away from the plane lying between the face of the bristles and the opposite face and the part of the region of the tip towards the base region of the head pivots in a region opposite to the direction of the bristles far from the plane lying between the face of the bristles and the opposite face of the head or vice versa In this embodiment said pivoting can be achieved, for example in a construction of the head in which tip end of the base region is in the shape of two members that partially surround a part of the tip region that extends in the direction of the base between them, with the junction between the tip region and the base region. For example, the tip end of the base region may be made in the form of two extended fork-like frames, with a part of the tip region between the two fork teeth and a junction between the region of the fork and the fork. tip and the base region. In an alternative construction of the head of this embodiment the base end of the tip may be in the form of two members that partially surround a part of the base region extending in the direction of the tip between them, with the junction between the tip region and the base region. For example, the base end of the tip region may be made in the form of a two-fork fork-like frame, with a part of the base region between the two fork teeth and a junction between the region of the fork and the fork. tip and the base region. For example, the tip region may be made generally in the form of 'C', 'U' or 'V' with its members towards the base region or in the shape of "Y" or its upper members of the And towards the base region. The part of the base region that extends in the direction of the tip may be between the members.

In a head construction in which the tip end of the base region is in the form of two limbs that partially surround a portion of the tip region that extend in the base direction between them, with an opening therebetween. At the tip region and the base region, the thin joints of flexible and resilient plastic material as described above can be provided between the respective members and tip region. In a head construction in which the base end of the tip region has the shape of two members that partially surround a part of the base region that extends in the tip direction between them, with an opening between the region of tip and the base region, the joints can be provided between the members and the base region. Adequately in said toothbrushes the joints can be provided in points diametrically opposed to one another to define a pivotal axis and to cause the pivoting in the plane in which the longitudinal axis is. Additionally or alternatively said joints may be provided at other points in the opening to cause pivoting about other axes. Between the base end of the head and the neck there is a resilient flexible joint. In a preferred embodiment, the joint comprises a mixed region of plastic material and an elastomeric material. In one embodiment, this mixed region may comprise, for example, a region of the construction described in WO 92/17092 and EP 0613636 (the contents of both are included herein). by reference) For example, the handle neck and head can be made integrally of plastic material and integrally connected between the base end of the head and the handle and between the neck and the head there can be one or more cuts in the material of plastic and the head and neck, extending into the surface of the plastic material of the cut using the union between the neck and the head, the cut containing a plastic material different from the plastic material of the head and necks and thus providing a flexible tooth joint between the head and the handle One or more cuts may comprise grooves or channels between the plastic material, which contains n the elastomepic material, for example one or more longitudinally extending channels. In said construction the cuts may be such that they form an integral union between the head and neck in the form of a narrow joining region, v gr, a resilient back of the material of plastic the narrow part being surrounded or flanked laterally by the elastomepco material The cut can be filled with an elastomep material to the full depth of the cut The cut can extend across the entire width of the toothbrush over at least part of the longitudinal extension The preferred forms of the mixed region described above are described in WO 92/17092 and EP 1613636 A Another embodiment of said mixed region is that described in EP 0648448 A (the content of which is included herein by reference) A preferred embodiment of said mixed region is that described in WO 97/24949, the content of which is included here by reference. Said mixed region at the end is provided in the toothbrushes, which has its head, neck and handle integrally made of plastic material so that, in the region of the neck between the base end and the head and the holding handle, a more thinned integral part which is in cross section thinned in relation to the immediately adjacent parts longitudinally of the neck and / or the head to which they are connected, the part of the bristle being laterally surrounded by a mass of elastomeric material bonded to the plastic material . The preferred forms of the last region of mixed material mentioned at the end they are as described in WO 97/24949. Preferably the flexible resilient bond between the base of the head and the neck is located at or immediately longitudinally adjacent the base of the head and the head-to-neck joints. Typically the thinned part can be in the form of a thin spine of plastic material extending longitudinally between the face surfaces of the longitudinally adjacent portions of the toothbrush. The thinned part can have a suitable cross section or a global shape to provide a degree desired or type of flexibility in the neck of the toothbrush The thinned part can have both of which are in the direction of the longitudinal axis of the toothbrush and are substantially parallel to the longitudinal axis. For example the thinned part can be a circular cross section and have a global cylindrical shape Alternatively the thinned part can be an oval shaped section, rectangular or cylindrical or capsule, the cross section with the long axis of said rectangular oval shape or capsule shape aligned in the same direction as the bristles or perpendicular to the bristles Normally the part of the head, v gr the base end of the head, to which the end of the head of the thinned part is connected may have a concave shape particularly as seen in plan (ie generally perpendicular to the longitudinal direction and generally parallel to the direction of the bristles) to the more deep of which the thinned part is connected Alternatively the part of the head to which the head end of the thinned part is connected may be a surface substantially perpendicular to the longitudinal axis In said constructions the last mentioned is the part of the neck to which the end of the handle of the thinned part is connected, it may have a convex corresonding shape or it may have a subs surface Alternatively, if the part of the head or neck the end of the head of the thinned part is connected it has a concave shape after the part of the head or neck to which the end of the handle of the thinned part is The connector may also have a concave shape of opposite curvature, so as to form a rounded cavity partially joined at its longitudinal ends by these two respective concave surfaces. In said constructions the thinned part may in effect join a groove aligned across the width of the same. neck of the toothbrush or between the head, v gr, at its base end and the neck of the toothbrush The groove in effect can be a channel on the parallel side or a channel on the curved side, v gr, with its end side of head and end side of the handle following a partial circular curve For example the thin part may be connected at its head end to the head end, the part of the base end of the head to which the head end of the thinned part is connected having a concave shape, towards the deepest part of which the thinned part connects and the part of the head or neck to which the end of the handle of the thinnest part is connected having a corresponding convex shape, so that the surfaces of the end face of the head of the neck and the base end of the head define a curved slot between them. Both surfaces of the face of a curve preferably follow a cre- atic curve which is substantially partly circular over substantially its entire length with the cusps of the growing part pointing generally toward the tip end of the dental septal. As seen from the side (it is dec r es a direction perpendicular to the longitudinal axis and the direction 1 of the bristles), the surfaces of the face can be aligned substantially perpendicular to the axis of longitudinal toothbrush, or they can be inclined at an angle not perpendicular to the axis. For example, the surfaces of the groove between the head end of the neck and the base end of the head can be tilted at an angle so that their extrapolation will be convenient on the surface of the lateral bristles of the toothbrush The thinned part can join the grooves symmetrically in relation to the thickness of the toothbrush (that is, the dimension generally parallel to the direction of the bristles) or it can be closer to one or the other side of the bristles or the reverse face of the head of the toothbrush for example to cause the joint to be more flexible in one direction than in others, or to impart a desired strength or flexibility to the joint thus formed. example as seen from the side (ie, from a direction perpendicular to longitudinal axis and the direction of the bristles) the thinned part can be closer the face of the bristles that the inverted face of the head For example the connection between the thinned part and the base end of the head may be completely or substantially in the part of the base end of the head and / or in that or in terms of thickness of the head and 'or neck are to the tad closest to the face of the bristles of the head and / or neck The cross section of the swollen part for example can be 0 1 - 0 75 suitably 0 25 - 0 5 of the cross section 1 of the longitudinally adjacent parts of the toothbrush immediately In a typical toothbrush (toothbrushes are generally all about the same size), the width of the groove (i.e., in the longitudinal direction of the toothbrush) may be about 1 -5 mm, typically 2 -3 mm, at a point where the toothbrush neck has a width (i.e. perpendicular to the longitudinal axis and the direction of the bristles) of about 4 -7 mm and a thickness (ie, perpendicular to the longitudinal axis and parallel to the direction of the bristles) of 3 - 5 mm Suitably therefore the thinned part, v gr, the spine, can have a relatively short flattened shape with dimensions of length dimensions of width on the scale of 2 1 to 1 2, usually 1 5 1 to 1 1 5 A suitable spine can therefore have a width (is say, across the longitudinal direction of the toothbrush) of approx 0 4 -5 mm normally of approximately 1 -3 mm and a length corresponding to the mentioned width before the groove in the crosses Preferably the mass is of a form that pronounces laterally beyond the line of the surface of the adjacent parts longitudinally of the neck or the head to which they are connected The mass of material eiastomepco can suitably be a rounded mass For example it can have a spherical symmetry an ellipsoidal or pear shaped spherical symmetry etc. Where the groove mentioned before it is a curved groove, the curve of the rounded mass can be the curve of the groove In one or both of the parts of the toothbrushes longitudinally adjacent to the mass the material of the plastic material can be enlarged in a mass in a way , ie, a curved surface, similar to this, that is to say the curve of the mass of elastomeric material and around which the mass of the elastomeric material can be formed. The rounded mass can project laterally in the direction perpendicular to the longitudinal axis of the dental brush. and generally in the direction of the bristles, between approximately 1 5 to 4, v gr 2 to 3 times the thickness of the pair immediately adjacent to the neck and / or base end of the head The rounded mass can project laterally, in the direction perpendicular to the longitudinal axis of the toothbrush and generally perpendicular to the direction of the bristles, between approximately 1 01 to 1 5, gr 1 1 to 1 3 times the width of the immediately adjacent part of the neck and / or the base end of the head The elastomeric material in the separation can modify the flexibility characteristics of the union v gr, providing a flexibility that separates between that of a joint of full plastic material and a joint of complete elastomeric material This can also modify the rolling characteristics of the head in relation to the handle The plastic material of the toothbrush and the elastomepco material where the joint is present between the base regions and the tip of the head when it is in a mixed region or at the junction between the head and neck when in a mixed region, it can be made of plastic and elastomeric material as is commonly used in two-component toothbrushes, e.g., as described in EP 0336641, which can be attached to plastic materials used for manufacturing of toothbrush handles. Said elastomeric material can be injected into the toothbrush mold shortly after the injection molding of the plastic material parts of the toothbrush so that the plastic material fuses and bonds with the elastomeric material. This is a generally known process. Suitable plastic materials include, for example, polyamides and polypropylenes. An example of a suitable polyamide is the material "Ultramid B3 ™" (made by BASF, Federal Republic of Germany), having a modulus of elasticity (DIN 53452) of 3000. An example of a suitable polypropylene is the material "Novoleno 1100 HX ™ "(made by BASF, Federal Republic Germany), which is a homopolymer and has a modulus of elasticity (DIN 53457) of 1400. Said polypropylene homopolymer can optionally be used in admixture with a polypropylene block copolymer, such as the material "Novoleno 2500 HX" '1"(made by BASF, Federal Republic of Germany), for example in a mixture of 80.20 by weight (1100 HX.2500 HX) .The suitable elastomeric materials include elastomers of the type natural or synthetic latexes, polychloroprene particle, natural rubber and silicones, for example the Santoprene ™ elastomeric material The toothbrush of the invention can be formed by generally conventional injection molding techniques, for example in which the "skeleton" of material The plastic is first made by injection molding, then the elastomeric parts, if present, are introduced by a subsequent injection molding step, in which the elastomer is injected as a hot fluid and attached to the plastic material. Self-evident injection molding, suitable by means of which toothbrushes can be formed having elastomeric materials disposed in place is separated on a plastic material is described in WO 94/05183. The bristles can also have a generally conventional construction, be arranged on the face of the bristles and the materials, they can be fastened on the face of the bristles by generally known techniques. The invention will now be described by way of example only with reference to the appended figures which show: Figure 1 is a plan view of the plastic material parts of the head and neck of a toothbrush of this invention. Figure 2 is a bottom view of the plastic material parts of the head and neck of a toothbrush of this invention.

Figure 3 is a side view of the plastic material parts of the head and neck of a toothbrush of this invention. Figure 4 is a partially plan view of the toothbrush head of Figure 1 showing the elastomer material in place. Figure 5 is a sectional view of the toothbrush head of Figure 3 showing the elastomer material in place. Figure 6 is a side view of a brush of this invention including elastomeric material and bristles. Figure 7 is a side view of another embodiment of the toothbrush of this invention. Figure 8 is a toothbrush of this invention in action, cleaning the teeth. Referring to Figures 1 to 6, a toothbrush 1 (overall) is shown which comprises the handle 2 and a head 3. The head has a base end 4 facing toward the handle 2 and a tip end 5 remote from the nose. base end 4. There is a neck 6 between the base end 4 of the head 3 and the handle 2. The head 3 is attached to the neck 6 at the base end 4 of the head 3. The head 3, neck 6 and handle 2 are arranged along an axis of the longitudinal toothbrush A-A. The bundles of the bristles 7, mounted in the receiving holes 8, extend from the face of the bristles 9 of the head 3.

The head 3 comprises a substantially rigid base region 10 which is attached to the toothbrush neck 6 and which extends from the base end 4 to the head 3 to a joint 11 located between the base end 4 and the tip end 5, and a tip region 12 extending from the tip end 5 of the head 3 to the joint 11. Both the base region 10 and the tip region 12 have bristles 7 (omitted for clarity in Figure 1 - 5). The joining region 11 is provided by a slot 13 between the tip region 13 and the base region 10 which is joined by the two strips 14 of the integral plastic material with the head material 3, the strips 14 being thinner than the thickness of the head 3 and extending between the tip region 12 and the base region 10 to join the slot 13. The strips 14 are considerably thinner than the thickness of the immediately adjacent parts 10, 12 of the head 3, of way that provides a flexible union. Between the end 4 of the head 3 and the neck 6 there is a joint 15 having the shape of a flexible mixed region 15 of plastic material and elastomeric material This flexible resilient mixed region 15 comprises an integral thinned part 16 connected in one of its ends to the neck 6 and at other ends to the base end 4 of the head 3. The part 16 has a thinned cross-section relative to the longitudinally adjacent portions of the shaft 6 and the head 3 to which it is connected. The part 16 is in the form of a thin spine of plastic material, of generally oval cross section through the longitudinal axis A-A, the long oval axes being generally aligned in the direction of the bristles, extending longitudinally between the base end 5 of the head 3 and neck 6 The thinned part 16 will be joined to the slot 17 aligned widthwise in the form of a curved lateral groove through the neck of the toothbrush between the base end 4 and the head 3 and the neck 6 of the toothbrush As shown in Figures 4, 5 6 the slot 13 is filled with an elastomeric material 18, which surrounds and encloses the strips 14 The slot 17 is also filled with an elastomeric material 19, so that the The thinned part 16 is laterally surrounded by a mass 19 of elastomeric material, which is attached to the plastic material and has a shape that projects generally spherically laterally beyond the line of the supra. The surface of the longitudinally adjacent portions of the neck 6 and the head 3 to which it connects This elastomer material is shown separately in Figures 4 and 5 to show more clearly how the strips 14 and part 16 are embedded in the elastomeric material. shows in Figures 1-6 the faces of the bristles 9 of the base region 10 and the tip region 12 are in the same plane. In the embodiment shown in Figure 7 the faces of the bristles 9 of the base region 10 and the tip region 12 are at an angle less than 180 ° with each other, so that these faces of respective bristles 9 are not in the same plane The ends of the bristles on the base region are in one plane and the end of the bristles on the tip region are also in one plane, the two planes not being coplanar but they are at an angle with each other corresponding to the angle between the faces of the bristles 9 of the base region 10 and the tip region 12. By the construction shown in Figure 7 the tips of the bristles are angled advantageously stop cleaning around the surfaces of the teeth, but also the spacing 20 between the ends of the bristles 7 of the base region 10 and the tip region 12 were reduced to a minimum. It will be evident from FIGS. 1-15 that the internal construction of the toothbrush of Figure 7 is similar The angle between the base region 10 and the tip region 12 is achieved by applying an angle corresponding to the plastic material portions of the brush dental, v gr, forming an angle in the plastic parts of toothbrush as they are molded, or molding the plastic parts and then flexing the plastic parts through the appropriate angle, before injecting the elastomeric material 18, and thus fix the toothbrush with the indicated angle between the base region 10 and the tip region 12 Referring to Figure 8 it is observed that the bristles 21 of the tip region 12 of the toothbrush of the invention particularly that of Figure 7 advantageously reach the backward facing surfaces 22 of the user's teeth 23

Claims (15)

1. CLAIMS 1. A toothbrush comprising a handle and a head, the head having a base end facing the handle and a remote tip end of the base end a region and a remote tip end of the base end, a region of neck between the base end of the head and the handle, the head joining the neck region at the base end of the head, the head, neck and handle being arranged together with a longitudinal axis of the toothbrush, the head having bristles extending from one side of the bristles of the head, characterized in that: the head comprises a substantially rigid base region joining the neck of the toothbrush and extending from the base end of the head to a flexible resilient bond located between the base end and the tip end and a tip region extending from the tip end of the head to the junction region, both the base region and the tip region taking rdas, the region of the tip being flexibly and resiliently joined in the region of the junction to the base region, and; Between the base end of the head and the neck there is a resilient flexible joint. A toothbrush according to claim 1, characterized in that the junction of the region of the tip and the base region is in a manner that allows the region of the tip to bend or rotate resiliently relative to the region of the tip. base during the brushing of the teeth 3 A toothbrush according to claim 1 or claim 2, characterized in that the junction region is in the longitudinal half of the head furthest from the base of the head 4 A toothbrush in accordance with claim 1, 2 or 3, characterized in that the tip region is also substantially rigid 5 A toothbrush according to any of the preceding claims, characterized in that in its non-taut condition, the face of the bristles of the tip region and the base region of the toothbrush are substantially coplanar 6 A toothbrush according to any of the preceding claims, characterized in that in its non-taut condition, the face of the bristles of the tip region and the base region of the toothbrush forms an angle less than 180 ° 7. A toothbrush according to any of the preceding claims, characterized in that the junction between the region tip and the base region comprises a mixed region having structural elements made of plastic material and an elastomeric material 8 A toothbrush according to claim 7, characterized in that the mixed region comprises an opening gap or slot in the head material between the tip and base regions which are joined by means of a combination of loins, strips or a thin continuous membrane of a flexible and resilient plastic material integral with the head and also by an elastomeric material in the opening, gap or groove . A toothbrush according to claim 8, characterized in that the mixed region comprises one or more strips of a plastic material integral with the material of the head, the strips being thinner than the thickness of the head and extending between the tip region and base region for joining an opening, gap or groove between the tip region and the base region, the gap or slot opening also containing an elastomeric material, attached to the sides of the gap and substantially filling the opening , separation or slot. A toothbrush according to any of claims 1 to 6, characterized in that the junction between the region of the tip and the base region comprises an opening, gap or groove in the plastic material of which the head is made, between the tip and base regions which are joined by means of one or more base regions which are joined by means of one or more thin dashes of flexible and resilient plastic material. A toothbrush according to any of claims 1 to 6, characterized in that the junction region between the region of the tip and the region of the base comprises an opening, gap and groove in the head material between the regions of point and assure that they are joined only by means of a complete or partial filling of an elastomeric material. 12. A toothbrush according to any of claims 1 to 11, characterized in that the head is constructed so that the tip region can be bent back resiliently relative to the base region, during the brushing of the teeth, around a toothbrush. axis of flexion oriented to the width that crosses the head in the region of the union. A toothbrush according to any of claims 1 to 11, characterized in that the tip region and / or the joint are constructed and positioned so that the tip region can rotate resiliently relative to the base region during the dental brushing, about a pivotal axis oriented in width that crosses the intermediate tip region between its tip end and its base end. A toothbrush according to any of the preceding claims, characterized in that the resilient flexible connection between the base end of the head and the neck comprises a mixed region of plastic material and an elastomeric material. A toothbrush according to claim 14, characterized in that the handle, neck, and head are integrally formed of plastic material and integrally connected between the base end of the head and the handle and between the neck and the head there is one or more cuts in the plastic material of the head and neck extending into the surface of the plastic material the cut crossing the boundary between the neck and the head, the cut containing an elastomeric material different from the plastic material of the head and the neck and thus providing a resilient flexible connection between the head and the handle 16 A toothbrush according to claim 15, characterized in that the junction between the head and the neck has the shape of a narrowed region of attachment of the plastic material , the narrowing being surrounded or flanked laterally by the elastomeric material 17 A dental brush according to claim 14, ca characterized in that the mixed region comprises an integral thinned part which is a thinned cross section relative to the immediately adjacent longitudinal portions of the neck and / or the head to which it is connected, the thinned part being laterally surrounded by a mass of elastomeric material bonded to the plastic material 18 A toothbrush according to claim 14, characterized in that the flexible connection is located at or immediately adjacent longitudinally to the base of the head and connects the head to the neck