CZ295811B6 - Toothbrush having controlled head movement - Google Patents

Abstract

In the present invention, there is disclosed a toothbrush (12) having a user manipulatable head (14) comprising: an elongated handle (18) having a longitudinal axis (A-A), an upper side (13) and a lower side (15); which handle (18) is comprised of a first relatively rigid, generally S-curved backbone section (26) and an opposed second and resiliently flexible elastomeric generally S-curved section (28); the first generally S curved section (26) extending at one end into a base (24) and at the other end extending into a neck portion (16) provided with a flattened head portion having an upper face (20) containing a plurality of bristle tufts (22) extended therefrom; the opposed S-curve sections (26, 28) defining an elongated figure 8 having a transverse aperture (30, 32) within each segment of the figure 8 with an upper and lower segment. The upper segment contains at least one upper aperture (30) and the lower segment contains at least one lower aperture (32) so that when pressure is applied to the first section (26) about the upper aperture (30) while simultaneously compressing the there-opposed second relatively resiliently flexible S-curved section (28) the head positions and adapts to the arcuate arrangement of teeth.

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to toothbrushes and more particularly to toothbrushes in which the position of their head can be controlled by balancing force on specific sections of their handle.

BACKGROUND OF THE INVENTION

Conventional toothbrushes include regular tufts of bristles, each having a first end that is engaged and attached to the brush head, and a second end that is loose and used for cleaning. The free ends of the different tufts form a surface that is capable of being slightly deformed by bending the bristles upon contact with the surface to be cleaned, but which is not capable of adequately adapting to a complex shape. Such a complex shape occurs in the mouth where the teeth are usually seated in a "C" curve in the upper and lower jaws, each row of teeth therefore having an outer convex curve and an inner concave curve.

The desire of users in brushing teeth, forcing the bristles to conform to the teeth, is expressed by the force of the brush to adequately deform the bristles according to the arcuate dentition profiles. Such a forceful action of the brush on the teeth only results in excessive wear of the tooth and gum surfaces, without adequate adjustment of the brush to the teeth to provide the desired cleaning.

Toothbrushes having a flexible neck positioned between a brush head comprising bristles and a handle that allow the brush to be adapted to the dentine profiles are described in the prior art. Examples of such flexible toothbrush necks are included in the toothbrushes disclosed in U.S. Patent Nos. 759,490 and 4,520,526. In U.S. Patent No. 759,490, neck flexibility is formed by inserting a flexible and resilient material between a fixed brush head and a fixed handle, wherein the flexible and the resilient material may be reinforced with a second material of that type. In U.S. Pat. No. 4,520,526, neck flexibility is provided by an alternative embodiment wherein either a portion of the material is removed from the top and bottom of the neck, or by providing an oval neck cavity extending from one side to the other. Such flexible and resilient toothbrush necks allow the bristle head to flex flexibly relative to the holder when the user applies excessive force, thereby reducing the risk of damaging the teeth and gums. Such flexible means, however, do not allow the user to control the brush head contour of the respective arc of the cleaned area in the mouth to prevent excessive force in the first case.

U.S. Pat. No. 4,333,199 discloses a toothbrush whose head is rotatably mounted on a coil spring over a recessed head, such that the head is adapted to rotate and tilt when it is attached to the teeth. Although such a bending operation will allow the brush head to generally follow the arc of the cleaned area in the mouth, it does not provide direct control to the user of the movement, tilt and rotation of the brush head.

PCT Publication WO / 89/10076 discloses a toothbrush allowing to vary the angle between the brush head and the handle to position the brush head parallel to the arcuate portion of the teeth. WO / 89/10076 discloses a toothbrush whose handle is pivotally attached to the head, the handle being a pair of spaced apart rigid upper and lower sides which are rotatably connected to each other so as to be longitudinally displaceable relative to each other. Alternatively, these mutually separated rigid upper and lower sides can be joined by means of a flexible spacer layer which also allows them to be longitudinally displaceable relative to each other. The use of such rotatably coupled elements, such as the handle and the head, controlled by lengthwise displacement of the fixed sides of the toothbrush to accurately control the position of the toothbrush head is extremely difficult. Such a lack of precise control is due to the fact of the pivotal connection where the lack of stiffness or resistance will tend to cause excessive movement of the brush head while

An alternative use of the elastic layer will limit the movement of the brush head, proportional to the degree of elasticity thereof.

Document EP 0 454 625 discloses a toothbrush comprising a head and a longitudinal handle in which the form and position of the head can be controlled by means of an oval wheel located in the holder that can rotate about an axis perpendicular to the longitudinal axis of the handle.

Therefore, there is a need in the art for a toothbrush in which the user can more accurately control the position of the toothbrush head for positioning the toothbrush head according to the arcuate configuration of the teeth.

SUMMARY OF THE INVENTION

These disadvantages are overcome by a toothbrush comprising an elongate handle that includes a first relatively rigid spine section curved in an "S" shape and an opposed second elastically flexible elastomeric section curved in a "S" shape; wherein the first section curved in the shape of the letter "S" passes at one end to the base and at the other end into a neck provided with a flattened head with an upper face portion comprising a series of tufts of bristles extending therefrom; wherein the opposed S-shaped curved sections define the shape of an elongated eight with an upper and a lower segment, the upper segment comprising at least one upper window and the lower segment at least one lower window extending transversely through the eight. To clean the teeth, the user can manipulate the head by exerting pressure on the first relatively rigid S-shaped spine section around the upper window while compressing the opposite second relatively resilient elastomeric S-shaped section to position the the front surface of the toothbrush with the bristles disposed therein and adapting them to the arcuate configuration of the teeth.

According to another embodiment, the cross-sectional areas of the upper window (s) and the lower window (s) are the same.

According to another embodiment, a toothbrush according to the invention may comprise an upper window (a) and a lower window (a) having an oval, circular or crescent shape.

The first relatively rigid spine toothbrush section of the invention, curved in an "S" shape, preferably exhibits a Shore A hardness in the range of 40 to 110, and the relatively resiliently flexible elastomeric section preferably exhibits a Shore A hardness in the range of 1 to 94.

According to another embodiment of the toothbrush of the invention, one segment comprises a single window and the other comprises a series of windows.

According to another embodiment, the toothbrush according to the invention comprises at least one window having an oval shape whose main axis is parallel to the longitudinal axis of the toothbrush or forms an acute angle with the longitudinal axis of the toothbrush.

According to another embodiment of the toothbrush according to the invention, each segment comprises a row of windows.

According to another embodiment, the windows have an oval shape, the main axis of which is parallel to the longitudinal axis of the toothbrush or forms an acute angle with the longitudinal axis of the toothbrush.

Obviously, the above features may be combined in various embodiments.

Furthermore, the invention relates to a method of positioning a toothbrush head according to the invention, comprising the step of positioning the toothbrush head by applying pressure to a first relatively stiff S-shaped spine section around the upper window while simultaneously pressing the toothbrush.

The second relatively elastically flexible elastomeric section curved in the shape of the letter "S" is formed.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a longitudinal perspective view of a first embodiment of a toothbrush of the present invention, with an arbitrarily curved bristle pattern, a sufficiently clearly arranged elastomeric section around the handle extending to the neck base, and a relatively stiff "S" curved spine section visible and an expanded base.

Figure 1A is a perspective view of the toothbrush of Figure 1, with added vertical and horizontal planes, wherein the vertical plane is perpendicular to the toothbrush face and extends along the longitudinal axis A-A.

Fig. 2 is a cross-sectional side view of a second embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an enlarged base.

FIG. 3 is a cross-sectional side view of a third embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an enlarged base.

FIG. 4 is a cross-sectional side view of a fourth embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an enlarged base.

FIG. 5 is a perspective view from the widened base to the head of the toothbrush of FIG. 1 with an arbitrarily curved bristle pattern.

FIG. 6 is a cross-sectional side view of a fifth embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an enlarged base.

Fig. 7 is a cross-sectional side view of a sixth embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an enlarged base.

Fig. 8 is a cross-sectional side view of a seventh embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an enlarged base.

FIG. 9 is a cross-sectional side view of an eighth embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and an extended base.

Fig. 10 is a cross-sectional side view of a ninth embodiment of a toothbrush of the present invention, with a typical flat bristle pattern and a typical tapered base.

DETAILED DESCRIPTION OF THE INVENTION

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in which the same reference numerals refer to the same or similar elements in the various figures, and in particular with reference to FIG. 1, a toothbrush 12 is shown. FIG. axis AA, with an upper side 13 and an opposite lower side 15, wherein the toothbrush 12 consists of a head 14 extending from the neck 16 with which it forms an integral part, the neck 16 extending from the handle 18 with which it forms an integral part, This handle 18 extends from the base 24 with which it forms an integral part. The head 14 has on its upper side 13 a face 20 from which tufts of bristles 22 project transversely to the longitudinal axis A-A.

-3GB 295811 B6

According to the present invention, the head 14 can bend with respect to the handle 18 in the vertical plane V shown in Fig. 1A, but is substantially rigid with respect to the handle 18 in the horizontal plane H shown in Fig. 1A. Such flexibility is due to the fact that the handle 18 is formed from a plurality of sections, being formed from sections of at least two materials having significantly different modulus of elasticity, one section being made of relatively rigid plastic and the other section being made of a resiliently flexible elastomer. The relatively rigid plastic section consists of a longitudinal spine section 26 generally curved in the shape of an "S" extending from the neck 16 of the toothbrush 12 to its widened base 24. The resiliently flexible elastomeric section 28 is also generally curved in the shape of an "S". is opposed to the longitudinal spine section 26, generally curved S-shaped, such that the openings of the S-shaped longitudinal spine 26 are closed by the S-shaped curves of the resiliently elastic elastomeric section28.

The longitudinal spine section 26 curved in the "S" shape together with the opposing resiliently flexible elastomeric section 28 in the "S" shape form a common shape of the general elongated figure eight. The interconnected S-shaped curves forming a general eight-shaped handle 18 define two windows 30, 32, an upper window 30, closer to the neck 16, and a lower window 32, closer to the base 24, with both windows 30, 32 approximately the same cross-sectional area.

The windows 30, 32 have a sufficient cross-sectional area such that when a user applies a relatively greater force to the relatively rigid spine section 26 around the upper window 30 than to the opposing relatively flexible section 28 around the upper window 30, or to the opposite relatively rigid spine section 26 around the lower window 32, the head 14 carrying the attached bristles deflects to a position in the direction of the upper side 13 of the toothbrush 12. The forces used in this operation of the user are shown in FIG. 1 by opposing arrows at acute angles to the longitudinal axis AA. Therefore, the user may apply a greater force at a suitable angle to the relatively resiliently flexible section 28 around the upper window 30 than to the corresponding relatively rigid spine section 26 around the upper window 30 so that the bristle-bearing head 14 deflects to the opposite direction, i.e. from the upper tent 13 of the toothbrush

12.

The interconnected S-shaped curve segments forming the handle 18 are shown in Figure 1 where they are substantially equidistant about the longitudinal axis AA, but in an alternative embodiment of the present invention, the S-shaped curve segments may be interconnected "S" placed more upstream of the longitudinal axis AA, as shown in Figure 2, or more downstream of the longitudinal axis AA, as shown in Figure 3. And further, while the windows 30 and 32 of Figure 1 are generally oval, with a relatively short transverse axis the longer longitudinal axis, where their longer longitudinal axis may be parallel or may be at an acute angle with the longitudinal axis AA of the toothbrush 12, these windows 30, 32 may be rounder, with a much longer transverse axis relative to their longer longitudinal axis as shown in Alternatively, the windows 30 and 32 may be crescent-shaped as shown in Fig. 8.

According to the present invention, the head 14, neck 16, S-shaped backbone section 26 is made by injection molding an integral product of relatively rigid polypropylene or other plastic with a similarly rigid structure such as polyamide, i.e. nylon or polyester, or a copolyester such as polyethylene terephthalate (PET), or polycyclohexylene dimethylene terephthalate which is acid-modified (PCTA), or cellulose plastic, or styrene acrylonitrile (SAN) or acrylonitrile butadiene styrene (ABS). The polypropylene or other rigid plastic preferably has a Shore hardness in the range of 40 to 110, more preferably 60 to 110 and most preferably 80 to 100.

A suitable polypropylene is commercially available from Huntsman Corporation, Longview, Texas, 75603, under the tradename Huntsman Polypropylene P4G3Z-039.

The relatively resiliently flexible elastomeric section 28 in the "S" shape can be made by injection molding of a variety of elastomeric materials, preferably thermoplastic elastomers (TPE). Acceptable TPE Materials for a Relatively Flexible Elastomeric S-shaped Section 28

These include styrene ethylene / butylene styrene (SEBS) styrene block copolymers such as styrene butadiene styrene, styrene isoprene styrene, and related copolymers, as well as a thermoplastic polyurethane (TPU) or a thermoplastic vulcanate (TPV) consisting of a blend of polypropylene and EPDM. (ethyl propylene diene monomers), which is commercially available under the name Santoprene, and is described in U.S. Pat. No. 5,393,796, or under the designation Vyram, another TPV consisting of a blend of polypropylene and natural rubber, both Santoprene and Vyram being elastomers marketed by Advanced Elastomer System LP, Akron, Ohio 44311. Another and preferred TPE is commercially available under the trademark Dynaflex G6713, marketed by GLS Corp., Cary, Illinois 60013. These and other suitable elastomers typically have a Burn hardness in the range of about 1-94, preferably about 15 to 60, and most preferably about 15 to 40.

The resiliently flexible elastomeric material may be oversprayed around the handle 18 as shown in cross-section as an elastomeric oversprayed area. The elastically flexible elastomeric S-shaped section 28 is shown in FIG. 4 as regions 38 and 40 which are separated in cross-section by a longitudinal relatively stiff spine section 26, generally curved in an S-shaped shape. The degree of flexibility of both the relatively rigid spine section 26 and the resiliently flexible S-shaped elastomer section 28 formed by the regions 38 and 40 can be further controlled by varying their thickness, i.e., to provide higher or lower flexibility.

If a substantially clean appearance is required for relatively rigid parts of the toothbrush 12, such as the head 14 of the toothbrush 12, the neck 16, the relatively rigid spine section 26, generally curved in the "S" shape, and the base 24, such as polyethylene terephthalate or copolyester such as PCTA or SAN polyester or cellulose plastic such as cellulose acetate propionate (CAP). If a substantially pure appearance is required for the resiliently elastic elastomeric portion of the toothbrush 12, i.e., the resiliently elastic S-shaped elastomeric section 28, certain TPE or TPUS materials or ethylene vinyl acetate (EVA) may be used. Preferred substantially pure TPE is commercially available from Teknor Apex Copany, Pawtucket, Rhode Island 02861, sold under the tradename 96-E0870A-03NT WAT CLR.

Alternative embodiments of the invention may include not only the two windows 30, 32 described above in the upper and lower segments of the general eight-shaped holder 18, but also in each segment a single window or a group of windows, i.e., three windows 30, 48, 50; four windows 32, 42, 44, 46; five or six windows. In the case of either a single window or such a group of windows in the handle 18, the relatively rigid spine section 26 forms the first side of each window or group of windows and the relatively resiliently flexible elastomeric section 28 forms the second of each window or group of windows. These windows may be generally crescent-shaped, generally oval or generally circular, with their longitudinal axis generally parallel to the longitudinal axis AA or inclined at an acute angle to the AA axis of the toothbrush 12. Such a plurality of windows may be substantially disposed substantially about the longitudinal axis AA of toothbrush 12 or both sides. An illustration of such alternative embodiments is shown in Figures 6, 7 and 9.

Since this embodiment of the present invention, comprising an extended base 24 with a gateway with the overall construction of the double parts, contributes significantly to the weight of a typical toothbrush 12, the base 24 may be hollow to minimize additional weight. As shown in FIG. 5, such a hollow base 24 may be formed by injection molding an inner relatively rigid polypropylene layer 34 surrounded by a resilient and flexible layer 36 that includes a resiliently flexible elastomeric material. In an alternative embodiment, as shown in FIG. 10, the present invention may comprise a typically tapered base 24 reducing weight gain.

The toothbrushes 12 of the present invention, consisting of a plurality of sections 26, 28, may be manufactured by a plastic injection technology well known in the art. For example, according to the present invention, a section 28 of resiliently flexible elastomeric material may be sprayed around the handle 18 in a second injection operation, after a first plastic injection operation after forming a frame or carcass consisting of a hard head 14 with bristles.

In this second plastic injection molding operation, the frame is placed in a second mold into which a resiliently flexible elastomeric material is injected around the handle 18, more specifically, around a relatively stiff spine section 26 extending from the base 24 to the base of the neck 16.

To facilitate these two operations in the manufacture of toothbrushes 12 by injection molding the plastics of the present invention can be accomplished by using an injection mold for injection molding in two operations. Such forms are commercially available from a variety of suppliers, including Machines Boucherie N.V., Izegem, Belgium; Anton Zahoransky GmbH & Copany, Todtnau, Germany; or Braun Formenbau GmbH, Bahlingen, Germany, where these molds can be mounted in typical plastic injection molding machines to carry out the injection molding process in two operations, which include 300 tonne plastic injection molding machines commercially available from Engel Vertriebsgesellschaft mbH, Schwertberg, Austria or Netstal-Maschinen AG, Nafel, Switzerland.

The toothbrush bristles 12 can be inserted into the face 20 of the toothbrush 12 using more advanced clamp technology as disclosed in U.S. Pat. Nos. 4,635,313, 4,637,660, 4,954,305, 5,045,267, 5,609,890, U.S. Pat. No. 5,390,984, US 5,533,791 and 5,823,633. Such clamp-free technology includes methods in which bristle tufts 22 are sealed into toothbrush head 14 by heating both bristle tufts 22 and toothbrush head 14, which are then joined together in the melting process, or where the ends of the bristle tufts 22 are pre-positioned in the injection mold prior to feeding the toothbrush material 12, which material is subsequently injected around the bristle tufts 22, blocking the bristle tufts 22 in place in the toothbrush head 14.

PATENT CLAIMS

Claims (18)

A toothbrush with a head (14) that can be handled by a user, comprising an extended handle (18) with a longitudinal axis (AA), an upper side (13) and a lower side (15), characterized in that the handle (18) comprising a first relatively rigid spine section (26) curved in an "S" shape and an opposing second elastically flexible elastomeric section (28) curved in an "S" shape; wherein the first S-shaped curved section (26) passes at one end to the base (24) and at the other end into a neck (16) provided with a flattened head portion with an upper face (20) comprising a plurality of tufts (22); that come out of it; wherein the opposed S-shaped curved sections (26, 28) define an elongated eight shape with an upper and a lower segment, wherein the upper segment comprises at least one upper window (30, 48, 50) and the lower segment at least one lower window (32, 42, 44, 46), so that when pressure is applied to the first relatively rigid spine section (26), the "S" curved around the upper window (30, 48, 50) while compressing the opposite second relatively elastically flexible elastomeric section (26). 28) The curved S-shaped head positions the head. Toothbrush according to claim 1, characterized in that the cross-sectional areas of the upper windows (30, 48, 50) and the lower windows (32, 42, 44, 46) are identical. Toothbrush according to any one of claims 1 to 2, characterized in that the upper windows (30, 48, 50) and the lower windows (32, 42, 44, 46) have an oval shape. A toothbrush according to any one of claims 1 to 2, characterized in that the upper windows (30, 48, 50) and the lower windows (32, 42, 44, 46) are circular in shape. Toothbrush according to any one of claims 1 to 2, characterized in that the upper windows (30, 48, 50) and the lower windows (32, 42, 44,46) are crescent-shaped. -6GB 295811 B6 Toothbrush according to any one of claims 1 to 5, characterized in that the first spine section (26) curved in an "S" shape has a Shore A hardness in the range of 40 to 110. A toothbrush according to claim 1, wherein one segment comprises a single window (30) and the other comprises a plurality of windows (32, 42, 44, 46). Toothbrush according to claim 7, characterized in that it comprises at least one window (30, 32, 42, 44, 46) having an oval shape whose main axis is parallel to the longitudinal axis (A-A) of the toothbrush. Toothbrush according to claim 7 or 8, characterized in that it comprises at least one window (30, 32, 42, 44, 46) having an oval shape whose main axis forms an acute angle with the toothbrush longitudinal axis (AA). . Toothbrush according to claim 7, characterized in that the windows (30, 32, 42, 44, 46) have a circular shape. A toothbrush according to any one of claims 7 to 10, characterized in that the relatively rigid spine section (26) has a Shore A hardness in the range of 40 to 110. A toothbrush according to any one of claims 7 to 11, characterized in that the relatively elastically flexible elastomeric section (28) has a Shore A hardness in the range of 1 to 94. A toothbrush according to claim 1, characterized in that each segment comprises a row of windows (30, 48, 50, 32, 42, 44, 46). Toothbrush according to claim 13, characterized in that the windows (30, 48, 50, 32, 42, 44, 46) have an oval shape, their main axis being parallel to the longitudinal axis (A-A) of the toothbrush. Toothbrush according to claim 13, characterized in that the windows (30, 48, 50, 32, 42, 44, 46) have an oval shape, their main axis being at an acute angle with the longitudinal axis (A-A) of the toothbrush. A toothbrush according to any one of claims 13 to 15, characterized in that the relatively rigid spine section (26) has a Shore A hardness ranging from 40 to 110. A toothbrush according to any one of claims 13 to 16, characterized in that the relatively elastically flexible elastomeric section (28) has a Shore A hardness in the range of 1 to 94. A method for positioning a toothbrush head according to claim 1, comprising the step of positioning the toothbrush head (14) by applying pressure to the first relatively rigid spine section (26) curved in the "S" shape. 'In the vicinity of the upper window (30, 48, 50) while compressing the opposite second relatively elastically flexible elastomeric section (28) curved in the shape of the letter "S".