MXPA00002982A - Toothbrush - Google Patents

Abstract

A toothbrush having a hinge located between its head and its handle, provided by a first and second hinge parts extending respectively from the head end of the toothbrush toward the handle end, and from the handle end toward the head end, in a longitudinally overlapping side by side relationship, the overlapping parts being able to rotate relative to each other through a restricted angle about an axis generally perpendicular to the longitudinal axis, the two parts being linked by a torsion element between them.

Description

TOOTHBRUSH FIELD OF THE INVENTION This invention relates to toothbrushes, particularly toothbrushes for use by manual action and which have a device modifying the flexibility in its handle.

BACKGROUND OF THE INVENTION Dental brushes are known which have flexibility modifiers in their handle, for example, the E.U. 5 054 154 describes the possibility of a toothbrush having a joint between its grip handle and its neck, that is, that part of the toothbrush between the handle and the head. Generally, however, the known toothbrush flexibility modifiers have been unable to focus the flexibility of the toothbrush to a precise point in the structure of the toothbrush, so that as a consequence, the toothbrush bends over the toothbrush. a loosely defined area. He too Accurate "adjustment" of the flexibility of the toothbrush can be difficult with known constructions.

SUMMARY OF THE INVENTION It is an object of this invention to overcome the aforementioned problems of known toothbrushes and to provide a toothbrush, on which flexibility can be focused in a precisely defined location and which can be easily adjusted independently of the selection of toothbrushes. particular construction materials for the toothbrush. According to this invention, a toothbrush has a head and a holding handle, with a neck between the head and the holding handle, all placed along a longitudinal axis of the toothbrush, bristles projecting from the head in a direction generally perpendicular to the axis of the toothbrush, having a hinge located between its head and handle, the handle being provided with a first hinge part extending from the head end of the toothbrush towards the handle end, and a second articulation part extending from the handle end towards the head end, said articulation parts, first and second, being installed in a longitudinally superposed side-by-side relation of a plane parallel to the longitudinal axis and the direction of bristles, the overlapping portions being able to rotate relative to each other through a restricted angle around an e It is generally perpendicular to the longitudinal axis and to the direction of the bristles, the two parts being connected by means of a torsion element between them. The joint can be located anywhere on the toothbrush between the head and the handle but is preferably located either between the joint and the neck or between the neck and the head. In this description, the head is defined as that part of the toothbrush that carries the bristles, the handle is defined as that part of the toothbrush that is held by the hand during use and the neck is defined as that part of the toothbrush between the head and the handle. Frequently, a toothbrush tapers over the neck region between the handle and the head. The direction of said relative rotation rotation is suitably from a resting position without initial tension to a position where the head of the toothbrush moves from its resting position at the tip of the bristles - direction of the head of the toothbrush, and the torsion element is suitably an element that is capable of providing tension force to return the head in the opposite direction towards, ideally, the rest position. Said displacement is caused by the pressure applied to the tips of the bristles by the brushing action of the user's teeth and consequently the application of pressure to it. In one embodiment, the toothbrush has a first joint part that extends from the head end of the toothbrush toward the handle end, and a second joint part that extends from the handle end toward the end of the toothbrush. head, respectively, the articulation parts, first and second, on either side of a plane parallel to and including the longitudinal axis. In another embodiment, the toothbrush has at least two articulation parts, first or second, respectively, either from the head end of the toothbrush towards the handle end, or from the handle end of the toothbrush toward the end of the toothbrush. head, and respectively either a second articulation part extending from the handle end towards the head end and between two said at least two first articulation parts or a first articulation part extending from the head end towards the handle end between two said at least two second articulation parts. The toothbrush of the invention can be provided as a handle end and a separate head end. In one mode these can only be connected by the torsion element. Alternatively, the toothbrush of the invention may have a handle end and an integral head end, with at least part of the torsion element formed integrally therebetween and bonding them. For example, a separate handle end and head end can be constructed having respective connecting portions cooperating together to retain the head end and the handle end together. For example, such connecting parts can cooperate by means of a quick-release cooperation, that is, where one or both of the connecting parts are elastic and the action of bringing the connecting parts together forces a ramp surface on an upper part. and beyond a ramp surface in the other part, in such a way that the disconnection of the connection parts requires new elasticity to achieve it. If the head end and the handle end are made of elastic plastic materials, the elasticity of such plastic materials can be used to provide such an elastic quick-fit connection. There may be an axis that defines the axis of relative rotation. This shaft may pass through a support hole, or fit into a support receptacle, respectively, through or in at least the first and second articulation part. For example, the support hole may be in the form of a hole in the shaft that passes completely through the respective first and / or second part. For example, the support receptacle can be in the form of a concavity, not passing the entire trajectory through the respective first or second part, and on which the end of the shaft is seated. Such an axis may be spaced apart or integral with the articulation part, first and second, and said relative rotation through a restricted angle may be about this axis. Alternatively, the parts may be linked by a torsion element, which may be integral with the first and / or second articulation parts. When the toothbrush is of the handle end construction and separate head end described above, the head end and the handle end can be made of different construction materials or materials colored differently to, for example, visually emphasize their building. The torsion element is an element that applies torsion against and to restrict the relative rotation of the parts, in such a way that the two parts can only rotate through a restricted angle in relation to each other, and this rotation generates a twisting effect elastic that tends to return the toothbrush to the original resting position of the parts, first and second. The torsion element thus imparts flexibility in the handle of the toothbrush, helping to reduce the possibility of excessive pressure of tooth brushing. One type of torsion element comprises a torsion element made of elastic material, for example made of the plastic material from which the head end and the handle end of the toothbrush are made, connected to the head end and the handle end, for example, connected integrally, and located between them. Such a torsion element may comprise a laterally extending torsion bar, that is, perpendicular to the direction of the longitudinal axis of the toothbrush. This torsion bar can be of any suitable cross section, for example, of non-circular cross-section around the axis of relative rotation of the head end and the handle end, made of an elastic material, which can be made entirely of the plastic material of the end of the handle or the head end of the toothbrush. Such a torsion bar may extend completely or partially across the width of the toothbrush between said first and second articulation parts. Such a torsion bar can link integrally, for example, the articulation parts, first and second. When one end of the handle and the head, respectively, is provided with such a torsion bar, the other end may be provided with an axle receptacle in and preferably through which the torsion bar extends, the section axle receptacle being. Transverse similar to the torsion bar. Suitably, such a torsion bar and shaft receptacle may also comprise the above-referenced connection parts, for example the torsion bar can be quickly placed in the shaft receptacle. Alternatively, the torsion bar can link the entire parts, first and second, as mentioned above. Another type of torsion element comprises an elastomeric material, attached to the head end and / or handle end, for example to one or both of said first and second articulation parts, and located therebetween. Methods of plastic and elastomeric bonding materials in toothbrushes are well known in the art of toothbrush manufacturing. For example, plastic and elastomeric parts can be brought together, for example as described in WO 98/27847. Such an elastomeric material can prevent unrestricted free rotation of the parts in relation to each other and can cause the parts to rotate relatively only through said restricted angle. Such an elastomeric material can be in the form of a filling material between the handle and head end, for example between the articulation parts, first and second. Such a filler material may be in the form of a layer, for example, interposed laterally between said overlapping portions. In this construction, the natural elasticity of the elastomeric material can serve to generate the required torsional force when the first and second articulation parts rotate relative to each other through their restricted angle. Additionally or alternatively, the elastomeric material may be in the form of a torsion bar extending between the head end and the handle end, eg, between the first and second hinge parts, and may be aligned with the shaft. , around which said relative rotation takes place through a restricted angle. Such a torsion bar is contorted as these parts rotate relative to each other, and thus a torsional force is generated. Such an elastomeric torsion bar can be attached to the plastic material of said first and second articulation parts. Such a filling material may comprise a composite structure of the elastomer and the plastic material of the toothbrush. In such a structure the plastic material can be in the form of structures extending within the filling material from the surface of the head end and the handle end, for example, the first and second articulation parts, which resist said rotation relative, to make filling material less flexible than it would be without such structures. For example, such a composite structure may comprise a mass of elastomeric material, and incorporated within this mass may be the parts of plastic material bonded with, for example, entirely made with, the first and / or second parts, such that when the parts, first and / or second, move relative to each other, for example, through the limited angle, the plastic parts try to move within the mass of the elastomer and thus experience a twisting force resulting from the natural elasticity of the mass of elastomer material. Such a construction may allow the bending of the toothbrush, preferably in the plane including the longitudinal axis and the direction of bristles, and may also provide the decrease in flexibility. In this way, flexibility in other directions such as width can be limited. The elastomeric material in this construction can consequently function as a fully floating support. Another type of torsion element comprises a thin layer of an elastic material, preferably integral with the plastic material of the articulation parts, first and second, and made of the plastic material of the toothbrush, between the head end and the handle end , for example, between the articulation parts, first and second, in such a way that the relative rotation of said parts as described above around the axis, applies a contortion force to the link, which therefore can, if it is of appropriate dimensions, generate a torsional force against said rotation. For example, such a link may comprise a spiral or helical structure of the plastic material that connects the head end and the handle end, for example, between and connecting the first and second link portions. Such spiral or helical structure can be made entirely with the plastic material of the head end and handle, for example, the articulation parts, first and second. The center of the spiral structure or the axis of the helical structure may comprise the axis, around which said relative rotation takes place. There may be an axis in the center of the spiral or helix, and the spiral (s) or helical structure (s) may be linked to its axis. Such a spiral structure may comprise a plurality of arms exiting in a spiral curve from a center of the spiral. Such a helical structure may comprise one or more coils of a helix surrounding a central helix axis. For example, if there is one articulation part, first and second, only located laterally between two articulation parts, first and second, respectively, there may be two such spiral or helical structures. For example, the articulation part, first and second, may have an opening therein, with the center of the spiral structure located at or near the center of the opening, and the outer ends of the spiral arms may be linked to the surface interior of the opening. When such spiral or helical structure is present, said relative rotation between the first and second articulation parts can completely wind the spiral or helix, and thus create a torsional force in the opposite contortion direction. In one form of such construction, the spiral structure may comprise a central axis defining the axis of relative rotation of the articulation parts, first and second, and interconnected, for example manufactured integrally with the articulation part, first and second, from which one or preferably more spiral arms, the spiral arm (s) being joined, preferably, integrally, respectively, with the articulation part, second or first. In one form of such construction, the helical structure may comprise a central axis defining the axis of relative rotation of the articulation parts, first and second, and linked, for example, made entirely with the first or second articulation part, from which one or more helical arms exit, the helicoidal arm (s) being joined, preferably, integrally, respectively, with the articulation part, second or first. The link can alternatively be made too thin so that it can not effectively make a practical contribution to the flexibility of the link, and can be provided primarily to allow the plastic parts of the toothbrush to be entirely molded of plastic material, for example, the The link can be formed by elastic resilient plastic material in an injection molding channel, the twisting method comprising an eiastomeric material between the first and second articulation parts. Such a slender bond can be made too thin so that it can flex completely freely or even be placed or cut when the toothbrush is used, for example, for the first time, whereby the elastomeric material acts as the torsion element, due that when such a link is used in a toothbrush of the invention, an elastomeric material as described above is also present between the parts. Another type of torsion member is provided by a construction in which the head end and the handle end are provided with respective torsion parts, at least one of which is elastic and such that when the head end and the end of handle rotate with respect to each other the respective torsion parts of each other, for example, as a result of the relative movement of one torsion part circumferentially relative to the other, and the elasticity generates a torsional force. Suitably, the elasticity of said torsion parts is provided by at least one of them comprising an elastomeric elastic material. For example, one or more of said torsion parts may comprise a first part extending radially from the relative axis of rotation of the head end and the handle end, and the other part may comprise a second part located above of the arc, followed by the first part during the relative rotation, in such a way that the parts, first and second, support each other during the relative rotation. One or both of said parts, first and second, may comprise an elastic elastomeric material. For example, alternatively, two of the torsion parts, first and second, respectively, can be located above the arc followed by the first or second torsion part during relative rotation, such that the parts, first and second, they hold each other during relative rotation. One or both of said parts, first and second, may comprise an elastic elastomeric material. The toothbrush of the invention may also include co-operative end stop means for encouraging or causing said parts to rotate relative to each other only through a restricted angle, for example, structures abutting each other in the limits of the angle restricted to avoid an additional relative rotation. Such structures can, for example, project from front surfaces of the overlapping portions, for example, the surfaces of the articulation parts, first and second, and can be respectively integral with such parts. When the link between the head end and the handle end, for example, between and linking the first and second articulation parts, comprises the aforementioned helical or spiral structure of the plastic material, then such a structure can also function as a means of end stop by virtue of the spiral or helix which is completely rolled up and prevents further rotation in a particular direction of rotation. By means of the toothbrush construction of the invention described above, the flexibility of the toothbrush can be made independent of the plastic material of the end of the toothbrush and, for example, can be determined by the composition, amount or shape of the elastomeric material. In addition, the flexibility of the handle can be determined by the position and construction of the joint, in order to focus the flexibility at a precise point on the toothbrush.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example only with reference to the accompanying drawings, which show: Figures 1 and 2, plan and side views, respectively, of a construction of the toothbrush of this "invention Figures 3 and 4, respectively, plan and side views of another construction of the toothbrush of the invention, Figures 5 and 6 show alternative constructions of the toothbrush joint of the invention in side views divided into parts. Figures 7 to 18 show partially exploded views of alternative toothbrush constructions of this invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figures 1 and 2, a toothbrush comprises a head 1, a holding handle 2 and a neck 3 between the head 1 and the handle 2, all of which are placed along a longitudinal axis of the brush dental AA From the head 1, bristles 4 are projected in a general direction of bristle B-B. The toothbrush is manufactured in the form of a separate head end 5 and a handle end 6. From the head end 5 a first articulation part 7 extends towards the handle end 6. From the handle end 6 it is extends a second articulation part 8 towards the head end 5. The two articulation parts 7 and 8 overlap longitudinally and lie side by side on opposite sides of a plane parallel to the longitudinal axis AA and towards the direction of bristles BB, the plane of the document being in Figure 1. The joint parts 7 and 8 are capable of rotating relative to each other through a small angle about a C-C axis. It will be noted that the hinge parts 7 and 8 stop very close to the handle end and the head end, respectively, leaving small spaces 9, 10 which provide clearance for the hinge parts 7 and 8 to rotate relative to each other . Between the two articulation parts 7 and 8 a torsion element 1 1 is located in the form of an elastomeric material bonded to each of the articulation parts 7, 8. The elastomeric material 1 1 is in the form of a layer thin in relation to the width of the toothbrush and in the shape of a disc. Found in this way, the toothbrush is able to flex around the CC axis, preferably in the direction plane of bristles BB, ie, in the plane of the document of Figure 2. In a modification of the construction shown in the figures 1 and 2, either or both of the articulation parts 7, 8 can be pierced with a hole (not shown) through which extends an axis (not shown) aligned with the axis CC and around which the relative rotation of the axes can occur. articulation parts 7, 8. Such an axis can be integral with an articulation part without perforating 7 or 8. Referring to figures 3 and 4, the corresponding parts in function with those of figures 1 and 2 are numbered correspondingly. From the handle end 6 of the toothbrush of FIGS. 3 and 4, two second parts 8 extend. From the head end 5 of the toothbrush of FIGS. 3 and 4, a first articulation part 7 extends, which extends between the two second articulation parts 8. It will be noted that the articulation parts 7 and 8, first and second, stop very close to the handle end and the head end, respectively, leaving small spaces 9, 10 that provide clearance so that the joint parts 7 and 8 rotate in relation to each other. Between the joint parts 7 and 8 there are two torsion elements 1 1 in the form of an elastomeric material joined to the articulation parts 7,8. In Figures 3 and 4, the installation of the hinge parts 7 and 8 can be reversed in such a way that the first two hinge parts 7 extend from the head end and a second single part 8 extends from the handle end 6 between the first two articulation parts 7, again with two torsion elements 1 1 between them. The elastomeric material 1 1 is again in the form of a thin layer relative to the width of the toothbrush and in the shape of a disc. In this way, the toothbrush is capable of flexing around the axis CC, preferably in the plane of the direction of bristles BB, ie, in the plane of the document of figure 4. In a modification of the construction shown in FIGS. Figures 3 and 4, one or more of the articulation parts 7, 8, first and / or second, can be pierced with a hole (not shown) through which extends an axis (not shown) aligned with the axis CC and around which the relative rotation of the joint parts 7, 8 may occur. Such axis or axes may be integral with a non-perforated joint part 7 or 8. Referring to FIGS. 5 and 6, the parts corresponding to the toothbrush Figures 1-4 are numbered accordingly. In figures 5 and 6, the articulation parts 7 and 8, first and second, are integrally linked by a thin plastic spine 12, which in figure 5 is circular in cross section and in figure 6 is rectangular in cross section. These connecting spines 12 allow the toothbrush to be molded integrally. The spines 12 can be made so thin that they contribute little or nothing to the elasticity or flexibility of the bond between the joint parts 7 and 8 and can also be cut off when the toothbrush is used. When the spines 12 are cut during use, although the toothbrush is provided with the spines that link the joint parts 7 and 8, with use, the joint parts 7 and 8 and the respective ends of head and handle are separated . The spines 12 can also alternatively function as torsion elements, the rectangularly cut spine 12 of FIG. 6 allowing fair control of the elasticity of the toothbrush handle by adjusting its dimensions. The spines 12 are contained within an additional torsion element 1 1 in the form of an elastomeric material. The elastomeric material 1 1 is again in the form of a thin layer relative to the width of the toothbrush and in the shape of a disc. In this way, the toothbrush is able to flex around the CC axis, preferably in the plane of the direction of the bristles BB, that is, in the plane of the document of FIGS. 5 and 6. Referring to FIGS. 7 to 15 , the parts corresponding to the toothbrush of figures 1 to 6 are numbered correspondingly. Figure 7 shows a toothbrush of construction similar to that of Figures 3 and 4, that is, with a first single articulation part 7 extending between two second articulation parts 8. Projecting laterally from the first part of articulation 7 there are two opposed camshafts 13 which fit into corresponding receptacle supports 14 in the two second articulation parts 8, allowing the first and second articulation parts 7 and 8 to rotate relative to each other around the axis DC. The handle end 2 and the head end 3 of the toothbrush can be processed separately and adjusted together, for example, by quickly placing the first joint part 7 between the two second articulation parts 8. There is a filling material of elastomeric material 1 1 between the articulation parts, first and second, 7, 8, which acts as a torsion element and which limits its relative rotation. Figure 8 shows a toothbrush of construction similar to that of Figure 7 and the corresponding parts are numbered correspondingly. Between the first articulation part 7 and the second articulation part 8 there are end stop means 15, 16 which are integral structures with and projecting from the surface of the respective part 7., 8 having surfaces of abutment 17, which adjoin to define the limits of relative rotation. There is a material for filling elastomeric material 1 1 (not shown for clarity) between the joint parts, first and second, 7, 8, which acts as a torsion element and which limits its relative rotation. Figure 9 shows a toothbrush with a first single articulation part 7 extending between two second articulation parts 8. The first and second articulation parts 7, 8 are drilled with coaxial holes 19, 20, through from which a shaft 21 made of the elastomeric material attached to the plastic material of the first and second articulation parts 7, 8 passes. In the relative rotation of the articulation parts, first and second, 7, 8, the axle 21 It acts like a torsion bar. Between the articulation parts, first and second, 7, 8, end stop means are in the form of grooves 22 in the first articulation part 7 and integral projections 23 in the grooves 22 of the surface of the second articulation means 8. The projections 23 only have limited movement in the slots 22, thereby allowing only limited relative rotation. Figures 10, 1 1 and 12 show all toothbrushes in which there is a first joint part 7 that extends between two second articulation parts 8, with a material for filling elastomeric material 1 1 between and attached to the parts of articulation, first and second, 7, 8. In figure 10, the filling material 1 1 is in the form of a layer interspersed between the parts 7, 8 and in figures 1 and 12 there is an axis of elastomeric material 21, similar to 21 of figure 9. In each of the three constructions shown in figures 10, 11 and 12, there are structures of plastic material 24 that extend inside the filling material 1 1 integrally from , in figure 10, the surface of the first articulation part 7 and, in figures 1 1 and 12, from the surface of the second articulation part 8. These structures 24 are in the form of blades, deflectors or propellers that resist broken said relative, in order to make the filling material 1 1 less flexible than it would be without the structures 24. Figures 13, 14 and 15 show toothbrushes of the invention in which there are integral links between the joint parts, first and second, 7, 8, which comprise a helical or spiral structure of the plastic material, the parts of the toothbrush corresponding to the parts of the toothbrushes of Figures 1 to 12 which have been correspondingly numbered above. There is also a material for filling elastomer 1 1 between the parts 7, 8. In figures 13, 14 and 15 a first joint part 7 extends between two second articulation parts 8. In figures 13 and 14, a axis 25 extends from the lateral surfaces of the first articulation part 7 and defines the relative rotation axis CC. In Figure 13, the shaft 25 is integrally connected to the second articulation part 8 by several spiral arcuate arms 26. In Figures 13 and 14, the second articulation part 8 has an opening therein, ie , conforming to an annular shape, the center 25 of the spiral structure being located at or near the center of the aperture, and the outer ends of the spiral arms 26 are bonded to the interior surface of the aperture. In FIG. 14, the shaft 25 is integrally connected to the second articulation part 8 by a single spirally arched arm 27. In FIG. 15, each lateral surface of the first articulation part 7 is connected to the second parts. of articulation 8 by an integral helical coil 28 of plastic material. When such helical or spiral structures are present 26, 27, 28, said relative rotation between the articulation parts, first and second, 7, 8, completely winds the spiral or helix and thereby creates a torsional force in the opposite direction of rotation. Referring to Figure 16, the parts corresponding to the toothbrush of Figures 1-15 are numbered accordingly. The toothbrush has a separate head end 5 and a handle end 6 constructed having respective connecting portions 29, 30 which co-operate together to hold together the head end 5 and the handle end 6. The connecting parts 29, 30 co-operate by means of a quick-release co-operation, that is, both connecting parts 29, 30 are made of elastic plastic material and the action of bringing together the connection parts 29, 30 force to a ramp surface 31 in a part 29 on and beyond a ramp surface 32 in the other part 30, so that the disconnection of the connecting parts 29, 30 again requires resilience to achieve this. The torsion element in the toothbrush of Figure 16 comprises a torsion bar 32 extending laterally, of noncircular cross section, about the relative rotation axis CC of the head end 5 and the handle end 6, made integrally of the plastic material of the head end 5 and the handle end 6 of the toothbrush. The torsion bar 32 extends across the width of the toothbrush between two second articulation parts 8, the connection portion 29 comprising a first articulation part having an axle receptacle 33 through which the torsion bar extends. 32 when the parts 29, 30 are connected together. The axle receptacle 33 is of cross section similar to the torsion bar 32. Referring to Figure 17, a toothbrush is shown in which the corresponding parts of the toothbrush of Figures 1-15 are numbered accordingly. The toothbrush has a separate head end 5 and a handle end 6 having a torsion member provided by a construction in which the head end 5 and the handle end 6 are provided with respective torsion parts, and a of said torsion portions 34 comprises a first radial portion 35 extending radially towards the handle 6 of the toothbrush from the relative rotation axis CC of the head end 5 and the handle end 6, and the other part 36 comprises a second part located above the arc followed by the first radial part during relative rotation, in such a way that the parts, first 35 and second 36, support each other during relative rotation. The second parts 36 are made of an elastic elastomeric material. The elastic force thus generated applies a twisting effect on the first part 35. The toothbrush of Figure 17 has a first articulation part 37, which is fitted between two second articulation parts 38 at the handle end when the head end 5 and the handle end 6 are connected together. The head end 5 and the handle end 6 function as connecting parts as the ramp surface 39 can be placed in the receptacle 40. The ramp surface 39 also acts as an axis in the receptacle 40 around which the head end 5 and the head end 6 can rotate relative to each other. Referring to Figure 18, the parts corresponding to the toothbrush of Figures 16 are numbered accordingly. The toothbrush has a separate head end 5 and a handle end 6 constructed having respective connecting portions 29, 30 which co-operate together to hold the head end 5 and the handle end 6 together. The connecting parts 29, 30 co-operate by means of a quick-positioning co-operation, that is, both connecting parts 29, 30 are made of elastic plastic material and the action of bringing the connecting parts 29, 30 together forces a surface ramp 31 in a part 29 on and beyond a ramp surface 32 in the other part 30, so that in order to disconnect the connection parts 29, 30 new flexibility is required to achieve this. The torsion element in the toothbrush of the figure 18 comprises a laterally extending shaft 41 of noncircular cross section about the relative rotation axis CC of the head end 5 and the handle end 6, made entirely of the plastic materials of the head end 5 and the end of the head 6 handle of the toothbrush. The shaft 41 extends across the width of the toothbrush between two disc-shaped end projections 42. The combination of the connecting part 29, the shaft 41 and the end projections 42 comprises a first articulation part. The end projections 42 are connected to second articulation parts 43 only by means of an elastomer disc 44 attached to both the end projections 42 and the second articulation parts 43. The elastomer 44 comprises a torsion element, so that the first and second articulation parts 42, 43 can rotate about a restricted angle in relation to each other. Any of the other types of torsional elements mentioned above with reference to the preceding figures may also be provided between the end projections 42 and the second articulation part 43. In use, the toothbrushes of Figures 1-18 operate in a Similarly. The pressure of the dental brushing applied to the head 1 of the toothbrush while holding the handle 21 causes the head end 5 and the handle end 6 to spring elastically around the joint, so that the first joint part 7 and the second articulation part 8 rotate relative to each other against a torsional force applied by the torsion element, and thereby relieve the excess brushing pressure. The direction of relative rotation, caused by the pressure applied to the tip of the bristles by the action of the user when brushing his teeth, is from an initial unstressed rest position, to a position where the head of the toothbrush moves from its resting position at the tip of the bristles - toothbrush head direction, which lies along the line BB downwards in the drawings of Figures 1 to 17. The torsion elements 11, 21, 26, 27, 28, 29, 30, 35, 36, 44 are capable of providing torsional force to return the head in the opposite direction towards the rest position. The degree of elastic articulation can be controlled by the dimensions of, and materials from which the toothbrushes are made, particularly the articulation parts, first and second 7, 8 and the torsion elements 11, 21, 26, 27, 28, 44

Claims (9)

1. A toothbrush with a head and a holding handle, with a neck between the head and the holding handle, all arranged along a longitudinal axis of the toothbrush, the bristles projecting from the head in a direction generally perpendicular to the axis of the toothbrush, having a joint located between its head and handle, characterized in that the joint is provided by a first articulation part extending from the head end of the toothbrush towards the handle end, and a second articulation part. which extends from the handle end towards the head end, said first and second hinge parts being installed in a side-by-side superposition relation on opposite sides of a plane parallel to the longitudinal axis and the direction of the bristles, being capable the superimposed parts of rotating relative to each other through a restricted angle around an ej and generally perpendicular to the longitudinal axis, the two parts being connected by means of a torsion element between them.

2. A toothbrush according to claim 1, characterized in that the joint is located between the handle and the neck.

3. A toothbrush according to claim 1, characterized in that the articulation is located between the neck and the tooth. A toothbrush according to any one of claims 1, 2 or 3 characterized in that the toothbrush has a first single articulation part extending from the head end of the toothbrush towards the handle end, and a second single part that it extends from the handle end towards the head end, the two articulation parts being respectively on either side of a plane ef which includes the longitudinal axis. and. A toothbrush according to any of claims 1, 2 or 3 characterized in that the toothbrush has at least two first and second joint parts respectively extending either from the head end of the toothbrush to the handle end, or from the handle end of the toothbrush toward the head end, and respectively either a second or first hinge part respectively extending from the handle end towards the head end, said first or second hinge part extending between the parts of the second or first respective articulation. 6, A toothbrush according to any of the preceding claims, characterized in that an axis defining the axes passes through a support hole, or is placed in a support receptacle, through or in at least the first or third joint part. second, and said relative rotation through a restricted angle is around the axis. A toothbrush according to any of the preceding claims characterized in that the torsion element comprises an elastomeric material, attached to one or both of said articulation parts, and located between them. 8. A toothbrush according to claim 7, characterized in that the elastomeric material is in the form of a layer sandwiched laterally between said overlapping portions. A toothbrush according to claim 7, characterized in that the elastomeric material is in the form of a torsion bar or shaft between the first and second articulation parts. A toothbrush according to claim 1 characterized by a separate head end and a handle end which are connected only by the torsion element. A toothbrush according to any of claims 1 to 10 characterized in that the torsion element comprises a thin integral link between said parts so that the relative rotation of said parts as described above about the axis applies a contortion force to the link . 12. A toothbrush according to claim 11, characterized in that the torsion element comprises a spiral or helical structure that connects the head end and the handle end., and said relative rotation between the first and second articulation parts completely winds the spiral or helix, and thus creates a torsional force in the opposite torsion direction. 13. A toothbrush according to claim 11, characterized in that the integral link is manufactured so that it can freely flex completely or even be placed or cut when the toothbrush is used. A toothbrush according to any of the preceding claims characterized in that a construction in which the head end and the handle end are provided with respective torsion parts, at least one of which is elastic, and such that when the end The head and the handle end rotate with respect to each other the respective torsion parts are supported against each other as a result of the relative movement of one torsion part circumferentially relative to the other, and the elasticity generates a torsional force. 15. A toothbrush according to claim 14, characterized in that one or more of said torsion parts comprises a first part extending radially from the relative axis of rotation of the head end and the handle end, and the other part comprises a second part located on the arc followed by the first part during relative rotation, so that the first and second parts are supported against each other during relative rotation. 16. A toothbrush according to claim 14, characterized in that two first and second torsion parts respectively are located above the arch followed by the first or second torsion parts during relative rotation, so that the first and second parts are supported by each other. during relative rotation. A toothbrush according to any of the preceding claims characterized by end stop co-operative means for encouraging or causing said parts to rotate relative to each other through a restricted angle. A toothbrush according to claim 17, characterized in that the end stop means comprise structures abutting each other within the limits of the restricted angle by means of which additional relative rotation is avoided. A toothbrush according to any of the preceding claims characterized in that a head end and a handle end having respective connecting portions which co-operate together to hold the head end and the handle end together. 20. A toothbrush according to claim 19, characterized in that the connecting parts co-operate by means of a quick-positioning co-operation where one or both connecting parts are elastic and the action of bringing the connection parts together forces a ramp surface in one part on and beyond a ramp surface in the other part, so that in order to disconnect the connection parts again elasticity is required to achieve it.