AU2003276237B2 - Handheld toothbrush - Google Patents

Description

C \NRPrtbl\DCC\KMH\338813_1 DOIC-6/10/2010 Handheld Toothbrush This invention relates to a handheld toothbrush. A handheld toothbrush of this type is known in the art from WO 01/43584 Al. In this handheld toothbrush tufts of bristles arranged on a ring area in the mid-region of the brush 5 head project from the surface close to the brushing side, the tufts extending all in opposition to the circumferential direction in an inclined relationship to the surface of the brush head. Disposed radially inside these tufts are further tufts that are arranged on a second ring area of smaller diameter and are equally inclined in the same direction as the outer tufts. 10 It is an object of the present invention to provide a handheld toothbrush in which during brushing a maximum possible number of bristle tufts penetrate between the teeth easily and perform a thorough cleaning operation, and this not only during an up and down movement but also during a back and forth movement of the handheld toothbrush. Furthermore it is an object to clean during brushing also the sides of 15 the teeth particularly thoroughly. A handheld toothbrush, with a brush head having a forward free end and a rearward portion, with an adjoining handle, in which at the forward free end of the brush head at least one bristle tuft of a first set extends away from the bristled surface of the brush head, with the second set of bristle tufts adjoining the first set in the direction 20 towards the rearward portion, the second set having several bristle tufts which protrude from the surface, are arranged serially on a ring area, and extend in the circumferential direction of the ring area at an angle of inclination (f) relative to the surface of the brush head, and the second set having in addition at least one further tuft that protrudes from the surface and extends within the several bristle tufts arranged on the ring area, with a 25 third set of bristle tufts that adjoins the second set of bristle tufts in the direction towards the rearward portion, the third set having several bristle tufts which protrude from the surface and are arranged serially on a ring area, and with the several bristle tufts of the third set being inclined in the circumferential direction in opposite to the direction of the several bristle tufts of the second set, is provided which enables the interproximal spaces 30 and their sides to be cleaned particularly well. This is accomplished in particular by arranging the outer bristle tufts of the second set, which are disposed on a ring area, in an inclined position in opposition to the bristle tufts of the third set and separating them - 1 - C \NRPoblCC\KMH\103R8I3_1 DOC-630/201 0 locally in longitudinal direction. With this arrangement of the invention particularly good penetration between the user's teeth is achieved by those bristle tufts that are inclined in the direction of movement of the handheld toothbrush, whilst the bristle tufts that are inclined in opposition to the direction of movement of the handheld toothbrush more or 5 less clean the surface of the tooth sides. When the toothbrush is moved in the other direction, the oppositely directed bristle tufts engage better between the teeth, yet from the other side, so that they are in a position to better clean the interproximal spaces from the other side. When the handheld toothbrush is moved back and forth, in particular those of 10 the bristle tufts on the ring area make particularly effective brushing engagement with the teeth as are disposed particularly more or less in the edge region of the brush head. This is so in particular because on the side edges individual tufts extend in the direction of movement of the handheld toothbrush, striking during brushing the interproximal spaces and the tooth surface transversely from above - similar to a scraper - whereby 15 plaque is removed from the tooth surface particularly effectively. The bristle tufts inclined in a direction transverse to the back and forth movement of the handheld toothbrush, which are arranged more or less in the inner region of the brush head, extend in a direction transverse to the direction of movement of the toothbrush, hence producing a sliding effect on the end faces of the teeth which are 20 easily accessible from the side. When the toothbrush is moved up and down in a direction perpendicular to the back and forth movement, that is, essentially parallel to the interproximal spaces, the scraping and sliding cleaning function in particular in the interproximal spaces is performed by the bristle tufts arranged in the mid-region of the brush head on the outer 25 ring area, whereby a better cleaning operation is accomplished in the interproximal spaces and also on the end faces of the teeth in a shorter period of time. By contrast, during this up and down movement the bristle tufts provided on the outer edge perform rather a sweeping movement directed at cleaning the surface of the tooth sides, because these tufts do not reach between the user's teeth as easily. Accordingly, 30 the toothbrush of the invention cleans the interproximal spaces within a shorter time than is the case with prior-art devices. Another benefit is that the first set of bristle tufts provided at the forward free end of the brush head services the rearmost molar region because this set is in the -2- C \NRPonb\DCC\KMM\3(X IK 11DOC-6/3/2010 foremost position when the brush head enters an oral cavity. By virtue of the third set of bristle tufts located on the ring area having at least one further tuft that extends within the tufts disposed on the ring area, the cleaning action performed by the outer bristle tufts provided on a ring area is aided by the third set of 5 bristle tufts supporting them from within as the bristles are pressed against the tooth surface, thus enabling them to better penetrate the interproximal areas and better clean the end faces. At the same time and additionally, the third set of bristle tufts is in a position to better clean the front surfaces of the teeth so that it is not necessary for the outer bristle tufts to perform the cleaning work alone. This has the added effect of 10 extending the useful life of the handheld toothbrush. A still further improved cleaning operation on the user's tooth surfaces is accomplished by the respective working ends of the bristle tufts of the second and third set that are disposed within the ring areas forming a nearly continuous 15 surface. Owing to the nearly continuous surface of the inner bristle tufts arranged within the ring areas of the outer bristle tufts, a particularly large area of the tooth surface is cleaned, so that even in the presence of an increased application pressure the bristles do not quickly bend away to the sides which would be of little advantage for the cleaning result and the durability. Furthermore, toothpaste is capable of adhering 20 better to the continuous surface and cannot run down along the bristle tufts. A continuous surface of the further bristle tufts of the second and third set is obtained by fanning out their free ends. As a result, particularly uniformly roughened, continuous cleaning surface is achieved on the free ends of the inner bristle tufts. In this arrangement the fine fiber structure has the effect of causing 25 interlacing of the free ends of the individual bristles of the tufts so as make them indistinguishable. The bristles of all the inner lying tufts hence form a joint tuft having just one common working surface that is capable of cleaning a large area of the tooth surface. In this arrangement the fanning out of the bristle tufts is performed by means of a rapidly rotating disk having on its surface small blades extending perpendicularly to 30 the disk, said blades operating to break up the working ends of the inner bristle tufts and to fan them out in such manner that their fine fibers become interlaced, thereby producing a continuous, yet roughened, surface. Particularly good cleaning results are obtained when the bristle tufts of the -3- C \NRPrb\DCC\KMH\M H Iti DOC-6/V/201) second and third set located on the ring areas are inclined at an angle of inclination (f and g, respectively) to the surface of the brush head of between 50 and 120, for example 80, because, owing to the small angle of inclination, the individual bristle tufts exert quite some resistance when pressed against the tooth surface, thus enabling a 5 user's hand to deliver a maximum possible amount of application pressure onto the tooth surfaces. This increases the effectiveness of a toothbrush, producing a better cleaning result in a shorter period of time. The bristle tufts of the second and third sets located on the ring areas have a common length L3 that is greater than the common length L4 of the further bristle 10 tufts lying within the tufts, resulting in a soft and elastic working surface of the handheld toothbrush in the presence of a low application pressure, the bristle tufts formed on the outer ring area first make an initial engagement with the tooth surfaces, and when the application pressure on the tooth surface is increased, the tufts that have not entered an interproximal space bend to an extent causing the other, shorter 15 tufts to be put to use. The user becomes aware of this condition by the handheld toothbrush becoming harder as pressure continues to be applied. It is then necessary for the application pressure on the handheld toothbrush to be significantly increased when it is desired to bend or deform all the bristle tufts on the brush head to accomplish a thorough cleaning operation. This tuft array improves the handling of the handheld 20 toothbrush because the user receives a better feedback enabling him to react promptly to a higher or lower pressure. A respective fourth set of bristle tufts extending transversely to the longitudinal direction of the brush head adjoins each of said first, second, and third set of bristle tufts. The fourth set of bristle tufts arranged between the second and third set of bristle tufts 25 supports the tufts of the second and third set during their brushing movements in small fringe regions in the sense of reinforcing the sides, that is, in addition to their own brushing function they contribute to increasing the flexural resistance of these bristle sets, thus providing for greater endurance of the handheld toothbrush of the invention. The bristle tufts of the fourth set have spaced apart bristle tufts in a side-by 30 side array, which have a greater hardness than the individual bristle tufts of the first to third sets further supporting this effect, so that overall the wear of the bristle tufts of the handheld toothbrush is reduced. The bristle tufts of the fourth set have a common length L5 whose dimensions -4- C .\N bl\DCC\KMH\ I3RRD3l DOC4/3020)10 lie between the lengths L3 and L4 or are equal to L4, which reduces wear still further by arranging the bristle tufts of the fourth set level with the bristle tufts lying within the bristle tufts provided on a ring area; however, they can also be longer than the bristle tufts lying within the bristle tufts provided on the ring area, while being shorter than the 5 bristle tufts provided on the ring area. In the first mentioned embodiment the bristle tufts are put to use simultaneously, thus causing hardening of the working surface of the tufts, while in the second embodiment the tufts are put to use with a slight delay, yet still contribute to hardening the working surface of the tufts adequately. They also have a supporting effect on the tufts of the first to third set provided between these tufts. 10 The bristle tufts of the fourth set protrude upwardly substantially vertically from the surface of the brush head. This effects a supporting action for the bristle tufts of the second set lying closest to these bristle tufts. By virtue of the vertical arrangement of the bristle tufts of the fourth set these can be arranged on the brush head in such manner that they are particularly close to the bristle tufts provided on the 15 ring area so that the supporting effect is obtained right at the beginning of the cleaning operation. The at least one frontal bristle tuft of the first set is inclined towards the forward end at an angle (b) relative to the vertical on the surface of the brush head, providing superior cleaning with the handheld toothbrush of the invention 20 because also the forward area of the brush head reaches deeper into the molar region, hence enabling also the rearmost region of the molars to be better cleaned. With the handheld toothbrush held in conventional manner, and with the first set having six bristle tufts whose free ends terminate on a common plane (E4) formed by the free ends of the second and third set of bristle tufts, the working end of the first set of 25 bristle tufts, which has its plane inclined, makes relatively snug engagement with the tooth surface to be cleaned, thus performing a uniform cleaning function of the molar surface without requiring a constant change in application pressure. The cross sections of the individual bristle tufts of the first to third sets are of an 30 essentially circular configuration, and the cross sections of the at least one bristle tufts of the first set and the further tufts of the second and third sets are essentially equal and have a diameter greater than the several bristle tufts of the second and third sets, providing a handheld toothbrush affording particular ease of manufacture, in which the tufts are of like cross section but yet of different bristle strength and bristle color. -5- C VWRPorbl\DCCM H3 M1038813- 1 DOC-6/30/2010 These features enable the tooling required for such a handheld toothbrush to be manufactured with greater ease so that the manufacturing cost of the handheld toothbrush can be reduced. An embodiment of the present invention will be described in the following 5 with reference to the accompanying drawings. In the drawings, FIG. 1 is a side view of a handheld toothbrush equipped with the bristle sets of the present invention; FIG. 2 is a top plan view of the handheld toothbrush of FIG. 1, taken in the direction of arrow X; 10 FIG. 3 is a partial side view of the brush head showing the complete bristle sets of FIG. 1, yet on an enlarged scale; and FIG. 4 is a partial top plan view of the brush head showing the complete bristle sets of FIG. 3. FIGS. 1 and 2 show a handheld toothbrush 1 that is comprised of an 15 elongated handle 2, a neck 3 of reduced cross section which adjoins the handle 3, and a brush head 4 adjoining the neck 3. The brush head 4 has a forward end 5 and a rearward end 6 between which four sets 8 to 11 of bristle tufts 21 and 24 to 30 extend upwardly from the surface 7 (FIG. 1), as also illustrated in FIGS. 3 and 4 on an enlarged scale. Provided on the upper side 12 of the handle 2 is a grip area 13 suitable for engagement 20 with a user's thumb, which grip area is slightly recessed within the surface 12 and includes raised ribs 14 that extend from the end close to the rearward free end in a direction transverse to the handle 2, are made from a thermoplastic elastomer material and bent slightly forwardly in the direction of the brush head 4. Referring now to FIG. 1, there is provided on the lower side 15 of the handle 2 25 level with the grip area 13 a further grip area 35 that is formed by lamella-type ribs 16 extending in a direction transverse to the longitudinal axis of the handheld toothbrush 1, said ribs being very narrow and accordingly of a yielding configuration similar to a cushion when individual fingers are pressed against them. The fine ribs 16 and the substrate 17 interconnecting the ribs 16 are equally fabricated from a thermoplastic 30 elastomer material that is injection molded onto the body 18 of the handle 2 and provided only in the forward and side regions of the handle 2. -6- C .RPortblDCC\KMH\03RM13_1 DOC6I10/201a As becomes apparent from FIG. 2, the handheld toothbrush 1 is of a symmetrical configuration having an axis of symmetry or center axis 23 that extends in the longitudinal direction of the handheld toothbrush 1. As seen in top plan view, the brush head 4 has the shape of an elongated oval having ends with a pronounced curvature, which form 5 the forward and rearward ends 5 and 6, respectively. The surface 7 of the brush head 4 from which the four sets 8 to 11 of bristle tufts 21 and 24 to 30 project extends at an upward inclination, forming an angle a with a depository area 19. The depository area 19 can be any surface of a piece of furniture. When the handheld toothbrush 1 is placed down on this depository area 19 as shown in FIG. 1, some of its bearing areas 10 36, 37 provided on its lower side 20 take support on the depository area 19, causing the toothbrush 1 to occupy a stable position in which the upper side 12 points substantially vertically upwardly, as shown in FIG. 1. The included angle a defined between the depository area 19 and the surface 7 is between 20 and 60, preferably 40. With such an angle a the handling of the handheld toothbrush 1 is particularly good 15 because it does not require a user's hand to be turned for the sets 8 to 11 of the bristle tufts 21 and 24 to 30 to engage against the user's tooth surfaces (not shown) relatively vertically. According to FIGS. 1 to 4 adjacent to the forward end 5 is a first set 8 of bristle tufts 21 that is inclined toward the forward end, forming an angle b with the vertical on 20 the surface 7. The angle b is between 50 and 9*, preferably 7*. The free ends 22 of the bristle tufts 21 form a common plane sloping upwardly at an angle c relative to the surface 7. The angle c is between 130 and 180, preferably about 150. The foremost point El of the foremost bristle tuft 21 is at a distance Li of about 12 mm to the surface 7. The rearmost point E2 of the two rearmost bristle tufts 21 is at a distance L2 of 10.5 mm 25 to the surface 7. The bristle tufts 21 of the first set protrude from the surface 7 so that they all combine to outline an essentially crescent-shaped cross section according to the top plan views of FIGS. 2 and 4. The first set 8 is formed by six bristle tufts 21 of which five tufts 21 extend parallel to the edge 38 and one tuft 21 is located within the five tufts 21, so that this set 8, when viewed from end-on, appears in an essentially 30 crescent-shaped configuration. Adjoining the first set 8 of bristle tufts 21 is a fourth set 11 of bristle tufts 24 extending in a direction transverse to the center axis 23 of the handheld toothbrush 1, as shown in FIGS. 2 and 4. The fourth set 11 is comprised of three tufts 24 35 essentially equidistantly spaced from the closest neighboring tufts 21 of the first set 8. -7- C :RPrbl\CC\KMMU)38X13-1 DOC40/2010 Accordingly, they lie on an arc of a circle and extend symmetrically to the center axis 23, with the middle tuft 24 being centrally located directly on the center axis 23. According to FIGS. 1 to 4 the fourth set 11 of bristle tufts 24 is adjoined by a second set 9 of bristle tufts 25 equidistantly spaced apart on a diameter D and inclined 5 anticlockwise at an angle f to the surface 7, as shown in FIG. 2. The angle f amounts to between 60 and 8", preferably about 70, while the diameter D is between 7 and 10 mm, preferably about 8.5 mm. The bristle tufts 25 are diametrically opposed to one another and comprised of eight to fourteen, preferably ten tufts 25. Extending from the surface 7 from radially within are furthermore four tufts 26 from the second set 9, 10 which are likewise diametrically opposed to one another and have their center in the same central point M as is the case for the tufts 25. The tufts 26 extend vertically upwardly from the surface 7. They lie on a common diameter D1 and are spaced apart by 90*, with two bristle tufts 26 extending centrally to the center axis 23. Next to this second set 9 is another fourth set 11 of two tufts 27 that extend 15 vertically to the center axis 23, are equidistantly spaced from the center axis 23 and project vertically upwardly from the surface 7. Adjacent to the bristle tufts 27 is a third set 10 of bristle tufts 28, which is likewise comprised of ten tufts 28 equally spaced apart circumferentially. Unlike the tufts 25 which are inclined anticlockwise, the tufts 28 are inclined clockwise circumferentially at an 20 angle g having the same inclination of 60 to 80, preferably 70, as previously indicated for the angle f of the second set 9. Radially disposed within the tufts 28 are again four tufts 29 protruding vertically upwardly from the surface 7. Greater details regarding the third set 10 are omitted because, with the exception of the opposite direction of inclination, the bristle tufts 28, 29 and their arrangement on the brush head 4 have the same 25 dimensions as previously indicated for the second set 9. Adjoining the third set 10 is again a fourth set 11 of three tufts 30, whereof the middle tuft 30 extends centrally to the center axis 23. The two outer tufts 30 are equidistantly spaced from the center axis 23. 30 While in FIGS. 1 and 3 the tufts 21 of the first set 8 project farthest in upward direction, the tufts 25 and 28 combine to form a common plane E4 (FIG. 3) that extends parallel to the surface 7. The relative distance L3 of the surface 7 to the plane E4 amounts to between 9 and 11 mm, preferably 10 mm. The relative distance -8- C NRPonbDCCiMH1OM13_1 DOC-630/2010 d of the plane E4 to the free ends 31 of the tufts 30, 27, 24 of the fourth set 11 is equal, amounting to between 0.7 and 1.1 mm, preferably 0.9 mm. The relative distance e of the plane E4 to the free end 32 of the bristle tufts 29 and 26 amounts to between 1.2 and 1.8 mm, preferably 1.5 mm. While the tufts 25 and 28 have a diameter i of 5 1.6 mm, the diameters h of the remaining tufts 21, 24, 26, 27, 29 and 30 amount to about 1.9 mm. The free ends 31, 32 of the tufts 30, 27, 24 and 29 and 26 extend equally parallel to the surface 7. Considering that the mode of operation of the handheld toothbrush 1 of the invention is already described in the introductory portion pertaining to the individual 10 patent claims, a new description is omitted at this point to avoid repetitions. According to FIG. 4 the bristle tufts 25 and 28 lie on an imaginary ring area 33 and 34, respectively, shown as thin lines in FIG. 4. The inner and outer diameters of the ring areas 33, 34 touch in the worst case the side walls of the tufts 25 and 28, respectively. Otherwise a distance can still be maintained between the edge of the 15 tufts 25 and 28 and, respectively, the inner and outer diameter of the ring areas 33, 34. It is, however also possible for a bristle tuft 25 and 28 to be disposed closer to the inner radius or closer to the outer radius of the ring area 33 and 34, respectively. The tufts 26 and 29 disposed within the tufts 25 and 28, respectively, are in such close proximity to each other that their free ends 32, in fanned out condition, form a 20 nearly continuous surface which is, however, not shown in FIGS. 2 and 4 for better clarity of illustration of the basic cross section of the bristle tufts 26, 29. The bristle tufts 24, 27, 30 of the fourth set 11 have a longitudinal dimension L5 extending from the surface 7 up to their free ends 31. The bristle tufts 26, 29 have a longitudinal dimension L4 extending from the surface 7 up to their free ends 32. Length 25 L4 is shorter than length L5, which in turn is shorter than length L3. Dimension L4 is obtained from L3 minus e, dimension L5 from L3 minus d. -9-

Claims (15)

1. A handheld toothbrush (1) with a brush head (4) having a forward free end (5) and a rearward portion (6), and with an adjoining handle (2), in which at the forward free end (5) of the brush head (4) at least one bristle tuft (21) of a first set (8) extends 5 away from the bristled surface (7) of the brush head (4), with a second set (9) of bristle tufts (25) adjoining the first set in the direction towards the rearward portion (6), the second set being comprised of several bristle tufts (25) which protrude from the surface (7), are arranged serially on a ring area (33), and extend in the circumferential direction of the ring area (33) at an angle of inclination (f) relative to the 10 surface (7) of the brush head (4), and said second set comprising in addition at least one further tuft (26) that protrudes from the surface (7) and extends within the bristle tufts (25) arranged on the ring area (33), characterized in that a third set (10) of bristle tufts (28, 29) adjoins the second set (9) of bristle tufts (25, 26) in the direction towards the rearward portion (6), said third set 15 being comprised of several bristle tufts (28) which protrude from the surface and are arranged serially on a ring area (34), and that the several bristle tufts (28) of the third set (10) are inclined in the circumferential direction in opposition to the direction of the several bristle tufts (25) of the second set (9).

2. The handheld toothbrush according to claim 1, 20 characterized in that the third set (10) of the bristle tufts (28) located on the ring area (34) furthermore comprises at least one further tuft (29) that extends within the tufts (28) disposed on the ring area (34).

3. The handheld toothbrush according to claim 2, characterized in that the respective working ends of the bristle tufts (26, 29) of the 25 second and third set (9, 10) disposed within the ring areas (33, 34) form a nearly continuous surface.

4. The handheld toothbrush according to claim 3, characterized in that the continuous surface of the further bristle tufts (26, 29) of the second and third set (9, 10) is obtained by fanning out their free ends (32). - 10- C.\NRPorblCC\KMH\303813- DOC.4/3/1010

5. The handheld toothbrush according to claim 1, characterized in that the bristle tufts (25, 28) of the second and third set (9, 10) located on the ring areas (33, 34) are inclined at an angle of inclination (f and g, respectively) to the surface (7) of the brush head (4) of between 50 and 120. 5

6. The handheld toothbrush according to claim 1, characterized in that the bristle tufts (25, 28) of the second and third set (9, 10) located on the ring areas (33, 34) have a common length L3 that is greater than the common length L4 of the further bristle tufts (26, 29) lying within said tufts (25, 28).

7. The handheld toothbrush according to claim 6, 10 characterized in that a respective fourth set (11) of bristle tufts (24, 27, 30) extending transversely to the longitudinal direction (23) of the brush head (4) adjoins each of said first, second and third set (8, 9, 10) of bristle tufts (21, 25, 26, 28, 29).

8. The handheld toothbrush according to claim 7, characterized in that the bristle tufts (24, 27, 30) of the fourth set (11) are 15 comprised of spaced apart bristle tufts in a side-by-side array, which have a greater hardness than the individual bristle tufts (21, 25, 26, 28, 29) of the first to third sets (8, 9, 10).

9. The handheld toothbrush according to claim 7, characterized in that the bristle tufts (24, 27, 30) of the fourth set (11) have a 20 common length L5 whose dimensions lie between the lengths L3 and L4 or are equal to L4.

10. The handheld toothbrush according to claim 9, characterized in that the bristle tufts (24, 27, 30) of the fourth set (11) protrude upwardly substantially vertically from the surface (7) of the brush head (4). 25 11. The handheld toothbrush according to claim 1, characterized in that the at least one bristle tuft (21) of the first set (8) is inclined towards the forward end (5) at an angle (b) relative to the vertical on the surface (7) of the brush head (4).

- 11 - C \NR orbI\DCC MMID1I813I 3 DOC-6/m0Z)I()

12. The handheld toothbrush according to claim 11, characterized in that the first set (8) is comprised of six bristle tufts (21) whose free ends terminate on a common plane (22) inclined at an angle (c) relative to the surface (7), and that said plane (22) extends above the plane (E4) formed by the free ends of the 5 second and third set (9, 10) of bristle tufts (25, 28).

13. The handheld toothbrush according to claim 2, characterized in that the cross sections of the individual bristle tufts (21, 25, 26, 28, 29) of the first to third sets are of an essentially circular configuration.

14. The handheld toothbrush according to claim 13, 10 characterized in that the cross sections of the at least one bristle tufts (21) of the first set and the further tufts of the second and third sets (26, 29) are essentially equal and have a diameter greater than the several bristle tufts (25, 28) of the second and third sets.

15 15. The handheld toothbrush according to claim 1, characterized in that the bristle tufts (25, 28) of the second and third set (9, 10) located on the ring areas (33, 34) are inclined at an angle of inclination (f and g, respectively) to the surface (7) of the brush head (4) of 8*. -12-