AU2004277995A1

AU2004277995A1 - Toothbrush having a uniform, sooth and continuous brush head

Info

Publication number: AU2004277995A1
Application number: AU2004277995A
Authority: AU
Inventors: Douglas J. Hohlbein; Bruce M. Russell
Original assignee: Colgate Palmolive Co
Current assignee: Colgate Palmolive Co
Priority date: 2003-10-02
Filing date: 2004-10-01
Publication date: 2005-04-14
Also published as: MXPA06001795A; KR20060091309A; CA2536531A1; BRPI0414474A; TW200524556A; CN1859859A; RU2006114775A; WO2005032302A1; AR046685A1; EP1672993A1; US20050071940A1; CO5650209A2

Description

WO 2005/032302 PCT/US2004/032463 TOOTHBRUSH HAVING A UNIFORM, SOOTH AND CONTINUOUS BRUSH HEAD BACKGROUND OF THE INVENTION 1. Field of the Invention 5 This invention relates to a toothbrush with bristles attached in such a manner to create a uniform, smooth and continuous wall thereof, and more particularly, to a toothbrush with means for supporting the toothbrush bristles to achieve a uniform, smooth and continuous wall of bristles using conventional staple bristle attachment methods. 2. Discussion of Related Art 10 Truly continuous smooth bristle bars are not new in the art (see, for example, U.S. Patent 6,276,021), but have only been achieved using new staple-less manufacturing technologies. These new manufacturing techniques, such as IMT, Fusion and AFT, are somewhat complex resulting in high capital cost and long lead times. It has therefore been found desirable to create continuous smooth bristle bars by utilizing conventional staple 15 technology due to its lower overall cost. Attempts have been made in the past with limited success to achieve smooth bristle bars utilizing conventional staple technology. For instance, simulated bristle bars have been achieved in the past using individual square tuft holders placed very close to one another, to minimize the space between tufts. Examples of this manufacturing technique 20 are described in U.S. Patent 5,446,940, owned by the same assignee as this application. A similar technique is described in U.S. Patent Publication No. 2001/0023516, with a "transverse wall" located between each tuft. A disadvantage of the above-noted prior art of U.S. Patent 5,446,940 is the small "bridge" of plastic required between each tuft. This "bridge" runs flush with the top 25 surface of the brush face, and causes a small gap A (see Fig. 1) in the bristles as they exit the tuft holes. As a result, the bristles cannot form a uniform, continuous and smooth wall, as the bristles "merge" from the tuft hole. It has therefore been found desirable to create a uniform bristle bar for bristles in a toothbrush with no gaps as the bristles leave the brush face. 30 The "transverse wall" of the manufacturing technique in U.S. Patent Publication No. 2001/0023516 is needed to maintain the bristles in a near upright position, so that subsequent tufts can be inserted without obstructing their access to their respective tuft WO 2005/032302 PCT/US2004/032463 2 hole. As is shown in Figure 2, if the transverse walls are simply removed and the bristles stapled into the resulting cavity, the bristles tufted into the blank cavity will disadvantageously tend to fall sideways into the cavity, due to a lack of lateral support. Further problems occur when inserting subsequent tufts, due to the non-vertical tufts 5 blocking the tuft "holes". Moreover, by use of this transverse wall, the aforementioned gap results so as to prevent a uniform, continuous and smooth wall of bristles. U.S. Patent Publication No. 2001/023516 further describes a method of using extra parts in the brush construction to create the "transverse walls", suggesting the use of metal staples or metal bars. It has therefore been found desirable to provide a toothbrush which 10 utilizes a single molded part for the construction of the tuft slot hole. Such a construction results in a stronger assembly, which is faster and less costly to produce. Based upon the foregoing, it has been found desirable to provide a toothbrush having a uniform, smooth and continuous wall of bristles, which uses traditional low cost staple techniques and ensures that once inserted, the bristles remain in a substantially 15 upright vertical orientation with respect to the longitudinal axis of the toothbrush to enable timely insertion of further bristles. OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a toothbrush which overcomes the disadvantages of the aforementioned prior art. 20 It is also an object of the present invention to provide a toothbrush which is manufactured so as to achieve a uniform, smooth and continuous wall of bristles using traditional staple technology. It is another object of the present invention to provide a method for making a toothbrush with a uniform, smooth and continuous wall of bristles which has lower 25 production costs. It is yet another object of this invention to provide a toothbrush which has adequate lateral support for the bristles tufted into the bristle cavity. It is a further object of the present invention to provide a toothbrush having a uniform, smooth and continuous wall of bristles, uses traditional low cost staple 30 techniques, and ensures that once inserted, the bristles remain substantially vertical with respect to the toothbrush to enable insertion of further bristles. It is an additional object of this invention to create a uniform bristle bar for bristles in a toothbrush which minimizes gaps as the bristles leave the brush face.

WO 2005/032302 PCT/US2004/032463 3 It is yet another object of this invention to provide a toothbrush which utilizes a single molded part for the constru-ction of the tuft slot hole. Various other objects, advantages and features of the present invention will become readily apparent from the ensuing detailed description and the novel features will 5 be particularly pointed out in the appended claims. SUMMARY OF THE INVENTION In accordance with the present invention, a toothbrush having a uniform, smooth and continuous wall of bristles is provided. The toothbrush of the present invention has a handle portion at one end thereof and a head portion at the other end thereof. The head 10 portion includes a brush face and a brush cavity with a plurality of lateral support members extending upwardly from the brush cavity so as to provide lateral support for the plurality of upwardly extending bristles arranged in a plurality of tufts. In applicant's toothbrush, at least one staple engages at least one of the plurality of tufts and affixes the at least one of the plurality of tufts between at least two of the lateral support members. In 15 order to prevent gaps between the bristles as they exit the bristle cavity, a leg of the lateral support member extends from a base of the cavity in the direction of the brush face to at least a bottom edge of the staple. This arrangement of the tufts in the lateral support member engaged by a staple enables the bristle of the tufts to engage one another at a point in the cavity below the brush face. As a result, the plurality of tufts so joined form a 20 substantially uniform continuous layer of bristles extending from the brush face. In accordance with another embodiment of the present invention, a toothbrush is provided having an elongated member having a head at one end and a handle at the other end, generally aligned along a central longitudinal axis, said head having a brush face including a cavity from which a plurality of bristles extend, said plurality of bristles being 25 arranged in a plurality of tufts so as to extend generally perpendicular to the central longitudinal axis; a plurality of lateral support members extending upwardly from a base of the brush cavity; attachment means provided in said brush cavity for engaging at least one of the plurality of tufts and for securing said one tuft between adjacent lateral support members, the 30 attachment means having a bottom edge and a top edge; and wherein each of said lateral support members extends from the base of the cavity so as to reach a predetermined height in the cavity which is between the height of the bottom edge of the attachment means and the brush face.

WO 2005/032302 PCT/US2004/032463 4 In accordance with a further embodiment of the present invention, a powered toothbrush is provided having an elongated member having a head at one end and a handle at the other end, generally aligned along a central longitudinal axis, said head having a brush face including a cavity from which a plurality of bristles extend, said plurality of 5 bristles being arranged in a plurality of tufts so as to extend generally perpendicular to the central longitudinal axis; a plurality of lateral support members extending upwardly from a base of the brush cavity; attachment means provided in said cavity at least for engaging one of the plurality of tufts and for securing said one tuft between adjacent lateral support members, said attachment means having a bottom edge and a top edge, and wherein each 10 of the lateral support members extends to a predetermined height from the base of the brush cavity so as to reach at least the height of the bottom edge of said attachment means in said brush cavity. In accordance with still another embodiment of the present invention, a lateral support member for holding bristles in a toothbrush is provided having a substantially 15 U-shaped formation formed in a cavity of the toothbrush, at least one leg of the U-shaped formation extending to a point between a bottom edge of a staple securing the bristles to the toothbrush and the brush face. The tuft in accordance with the present invention may be engaged by arranging the staple between a single lateral support member and a side edge of the cavity. Moreover, 20 the lateral support members may extend to a point between the brush face and the bottom edge of the staple. Given the outward forces created by the presence of a staple, it is preferred to have the height of the lateral support wall rise above the bottom of the staple. However, to ensure that the bristles between adjacent tufts are in full contact (with no gaps) prior to 25 leaving the tuft hole, the lateral support wall should stop short of the top surface of the brush face. The final convergence point of these bristles is controlled by the top-most width of the lateral support wall, the distance between the top of the wall and the brush face, and angle of the sides of the wall. 30 BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description, given by way of example, but not intended to limit the invention solely to the specific embodiments described, may best be understood in conjunction with the accompanying drawings in which: WO 2005/032302 PCT/US2004/032463 5 Figure 1 is a cross-sectional view of a prior art method for attaching bristles in a bristle cavity as taught in U.S. Patent Appln. Publication No. 2001/0123516. Figure 2 is a cross-sectional view of a prior art method for attaching bristles in a bristle cavity without any support members. 5 Figure 3 is a front perspective view of a preferred embodiment of a toothbrush in accordance with the teachings of the present invention. Figure 4 is an enlarged top view of the head portion of the toothbrush shown in Figure 3 with the bristles removed. Figure 5 is a cross-sectional view of a first preferred embodiment of an assembly 10 and process for providing a uniform, smooth and continuous wall of bristles in the brush cavity of the toothbrush of Figure 3. Figure 6 is a cross-sectional view of another preferred embodiment of an assembly and process in accordance with the teachings of this invention for providing a uniform, smooth and continuous wall of bristles in the brush cavity of the toothbrush of Figure 3. 15 Figure 7 is cross-sectional view a of another preferred embodiment of an assembly and process in accordance with the teachings of this invention for providing a uniform, smooth and continuous wall of bristles in the brush cavity of the toothbrush of Figure 3. Figure 8 is a cross-sectional view of another preferred embodiment of the assembly and process in accordance with the teachings of this invention for providing a uniform, 20 smooth and continuous wall of bristles in the brush cavity of the toothbrush of Figure 3. Figure 9 is a top view of another preferred embodiment an assembly and process in accordance with the teachings of this invention for providing a uniform, smooth and continuous wall of bristles in the brush cavity of a toothbrush having a curved lateral support wall. 25 DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS OF THE PRESENT INVENTION Referring now to the drawings, wherein like reference numerals represent like features in the several views, the preferred embodiments of a toothbrush in accordance 30 with the teachings of the present invention are shown in Figs. 3-6. Figs. 3-6 relate to a toothbrush having a uniform, smooth, and continuous wall of bristles. However, designs other than those specifically set forth herein are also contemplated which would similarly WO 2005/032302 PCT/US2004/032463 6 provide a toothbrush having a uniform, smooth, and continuous wall of bristles and still be in accordance with the teachings of the present invention. Referring now to Fig 3, there is provided a manual toothbrush 1 including an elongated handle 2 on one end and a head 10 on the other end. The handle 2 may be 5 conventional in shape and include features such as ergonomic sizing, grasping features, bends, and coloration as desired by the designer. The head 10 in Fig. 3 is shown in a octagonal shape, however, other shapes including round, oval, square, etc., may be used without departing from the scope of this invention. Extending from the head 10, substantially perpendicular to the longitudinal axis 3 of the toothbrush 1 are a plurality of 10 bristles 18 which as will be described in more detail below formed as a uniform, smooth, and continuous wall. Fig. 4 shows a top view of the head 10. The head 10 includes a cavity 12. The cavity 12 has a plurality of lateral support members 14 formed therein, and is defined by an edge 26 forming the outer perimeter of the cavity 12. The lateral support members 14 15 are preferably U-shaped, but other shapes may be utilized without departing from the scope of the invention. The head 10 also includes a brush face 16, which forms the top most surface of the head 10. Typically, the bristles 18 extend substantially perpendicular to the longitudinal axis 3 of the toothbrush 1 from the bottom 34 of the cavity 12 to a point above the brush 20 face 16, as shown in Fig. 5. In a preferred embodiment of Fig. 5, a staple 22 is used to affix the bristles 18. Preferably a plurality of individual bristles 18 are combined to form a tuft 20. The tuft 20 is inserted into the cavity 12, arranged between a pair of legs 23 and 25 of adjacent lateral support members 14 or between a leg and the edge 26 of the cavity 12, and affixed to the 25 toothbrush head 10 by the staple 22. The staple includes a top edge 30 and a bottom edge 28 thereof. It is preferable that the bristles are bent in half substantially at a center point of each of the bristles and arranged so that the bend portion is inserted into the lateral support member 14. Preferably still, the nurnber of bristles 18 grouped together to form a tuft 20 is sufficient to form a close fit in the lateral support member 14. As such, the outer 30 bristles 18 of a tuft 20 will have a bend radius substantially similar to the radius of the lateral support member 14. The bottom edge 28 of the retaining staple 22 forms the center of the WO 2005/032302 PCT/US2004/032463 7 bend radius of the bristles 18 as shown in Fig. 5. Given the outward forces created by the presence of the staple 22, it is preferred to have the height of the lateral support member 14 rise above the bottom edge 28 of the staple 22. However, to assure the bristles between neighboring tufts 20 are in full contact prior to exiting the cavity 12, the legs 23, 25 of the 5 lateral support members 14 must stop short of the brush face 16. However, the edge 26 which may form a portion of the lateral support member may still rise to the level of the brush face 16. There is no convergence point on the edge 26 side of the lateral support member 14, thus the edge 26 preferably extends from the bottom 34 to the brush face 16. The final convergence point of the bristles 18 is controlled by the top 10 most width of the lateral support member 14, and more specifically the width of the legs 23 and 25, the distance between the top of the lateral support member 14 and the brush face 16, and the angle 8 of the legs 23 or 25 of the lateral support member 14 with respect to the bottom 34. As shown in Fig. 5, the legs 23 or 25 of the lateral support member 14 are 15 relatively thick and maintain a substantially constant thickness. In this embodiment, the height of the lateral support member 14 is considerably less than the surface height of the brush face 16, and does not extend as close to the brush face 16, as in the embodiment shown in Fig. 6. As a result, the point of convergence 32 of the bristles 18 is lower in the cavity 12 for the embodiment of Fig 5 . 20 Fig. 6 shows another embodiment wherein a plurality of lateral support members 14 are formed along the bottom 34 of the cavity 12. The lateral support members 14 are formed of at least one leg 23a and a substantially concave base 24a. The lateral support members may include a second leg 25a, or alternatively, the edge 26 of the cavity 12. As shown in Fig. 6, the legs 23a and 25a extend to a point approximately the same height as a 25 top edge 30 of a staple 22. As shown in Fig. 6, when the lateral support member is tapered such that the legs 23a or 25a is relatively thick at its base and becomes thinner and thinner as it proceeds towards the surface of the brush face 16a, the lateral support member 14 rises much closer to the surface of the brush face 16a than the lateral support member of Fig. 5. This results 30 in the point of convergence 32 being higher from the cavity 12. In this embodiment, however, the point of convergence 32 remains below the surface of the brush face 16a. Figure 7 depicts a further embodiment of the present invention, where the lateral support member 14 extends towards the brush face 16 to a point beyond the top surface 30 WO 2005/032302 PCT/US2004/032463 8 of the staple 22, but below the level of the brush face 16. As with the example shown in Fig. 6, the convergence point is higher, in the cavity 12. Another aspect of the present invention is shown in Fig. 8. The top surface of the lateral support member may be formed in a non-flat orientation. This results in greater 5 general stability for the bristles 18 caused by the height of the legs 23. This non-flat orientation also increases the uniformity and smoothness of the toothbrush as the bristles extend past the brush face 16 compared to straight lateral support members 14 having legs extending to substantially the same height as those of Fig. 8. This effect is caused by the dropping of the convergence point 32 for the bristles between the legs 23 in the non-flat 10 section of the lateral support member 14. While the foregoing examples have been discussed with respect to lateral support members having a substantially straight formation and disposed substantially longitudinally on the axis 3, other orientations are considered within the scope of the present invention. For example, Fig. 9 depicts a portion of a toothbrush head 10 having a 15 lateral support members 14 formed in a curved orientation. It should be understood that the objective reached above can also be achieved by a construction involving an increase in the thickness of the head 10 perpendicular to the longitudinal axis 3 of the toothbrush 1. This results in an increase in the depth of the cavity 12, which in turn provides for an increase in the height of the edge 26 around the 20 cavity 12. This increase in height effectively insures that the point of convergence of the bristles remains below the brush face, thus eliminating the gap A that is produced when using the methods shown in prior art of Fig. 1. In this embodiment, the edge 26 extends from the bottom 34 to a point minimally as high as the point of convergence 32 of neighboring tufts 20. The lateral support members 14 may extend beyond the top edge 30 25 of the staple 22, but not as far as the brush face 16. This results in a toothbrush having a uniform, smooth, and continuous wall of bristles 18 at the brush face 16. However, while this method is contemplated, in the preferred embodiment the thickness of the head 10 is not increased as this presents a more desirable toothbrush, requiring less material and resulting in a more compact toothbrush for easier use. 30 The preferred materials for construction of the toothbrush 1 of the present invention include a wide variety of moldable or injectable plastics such as thermoplastics. It is preferable that the toothbrush and head are molded as a single thermoplastic component. Alternatively, multiple plastic components could be formed and joined after WO 2005/032302 PCT/US2004/032463 9 formation. It is further preferable that the lateral support members 14 are formed during the molding of the head 10 and are integral therewith. Alternatively, the lateral support members 14 could be formed as part of the handle 2 and integrated with the head 10 when the components are assembled. Still further, the 5 lateral support members 14 could be formed separately and then added to the toothbrush as a component. It is a further embodiment of the present invention that the head 10 is arranged on a powered toothbrush (not shown). The result is a powered toothbrush having a head 10 with a uniform, smooth and continuous wall of bristles affixed to one end and a handle 10 disposed on the other end of the powered toothbrush. Typically, the handle comprises a powering means for actuating the head 10 of the powered toothbrush. The actuation may be oscillating, rotary, reciprocating, or simple vibration, or a combination of motions. The head 10 may be removable from the power providing handle or formed of a single integrated unit as desired. 15 The desired objects of the present invention have been met by providing a toothbrush having a uniform, smooth, continuous wall of bristles while using lower cost traditional staple technology. This is accomplished by controlling the height of the legs 23 or 25 of the lateral support members 14. Limiting the height of the legs to a point below the edge 26 of the cavity effectively eliminates gaps between the tufts as they extend past 20 the brush face. Further, there is provided sufficient lateral support for the bristles to ensure that the bristles extend substantially perpendicular to the longitudinal axis of the toothbrush, and allow for easier insertion of subsequent bristle tufts when using traditional staple affixing methods. Although the invention has been particularly shown and described with reference 25 to certain preferred embodiments, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

Claims

1. A toothbrush comprising: an elongated member having a head at one end and a handle at the other end, generally aligned along a central longitudinal axis, said head having a brush face including 5 a cavity from which a plurality of bristles extend, said plurality of bristles being arranged in a plurality of tufts so as to extend generally perpendicular to the central longitudinal axis; a plurality of lateral support members extending upwardly from a base of the brush cavity; 10 attachment means provided in said brush cavity for engaging at least one of the plurality of tufts and for securing said one tuft between adjacent lateral support members, said attachment means having a bottom edge and a top edge, and wherein each of the lateral support members extends to a predetermined height from the base of the brush cavity so as to reach at least the height of the bottom edge of 15 said attachment means in said brush cavity.

2. The toothbrush of claim 1, wherein the lateral support member extends to a predetermined height between the bottom edge of the attachment means and the brush face.

3. The toothbrush of claim 1, wherein at least one of the plurality of tufts is 20 affixed by the attachment means between one of the plurality of lateral support members and a side edge of the brush cavity.

4. The toothbrush of claim 1, wherein attachment means is a metal staple.

5. The toothbrush of claim 1, wherein the lateral support members are substantially U-shape. 25

6. The toothbrush of claim 1, wherein the lateral support members enable the bristles of the plurality of tufts to contact one another at a point in the cavity below the brush face.

7. The toothbrush of claim 1, wherein said attachment means forms a substantially uniform continuous layer of bristles extending from the brush face. 30

8. The toothbrush of claim 1, wherein the lateral support member has a non flat top surface.

9. The toothbrush of claim 1, wherein the lateral support walls are curved.

10. A powered toothbrush comprising: WO 2005/032302 PCT/US2004/032463 11 an elongated member having a head at one end and a handle at the other end, generally aligned along a central longitudinal axis, said head having a brush face including a cavity from which a plurality of bristles extend, said plurality of bristles being arranged in a plurality of tufts so as to extend generally perpendicular to the central longitudinal 5 axis; a plurality of lateral support members extending upwardly from a base of the brush cavity; attachment means provided in said cavity at least for engaging one of the plurality of tufts and for securing said one tuft between adjacent lateral support members, said 10 attachment means having a bottom edge and a top edge, and wherein each of the lateral support members extends to a predetermined height from the base of the brush cavity so as to reach at least the height of the bottom edge of said attachment means in said brush cavity.

11. The toothbrush of claim 10, wherein the lateral support member extends to 15 a predetermined height between the bottom edge of the attachment means and the brush face.

12. The toothbrush of claim 10, wherein at least one of the plurality of tufts is affixed by the attachment rneans between one of the plurality of lateral support members and a side edge of the brush cavity. 20

13 The toothbrush of claim 10, wherein attachment means is a metal staple.

14. The toothbrush of claim 10, wherein the lateral support members are substantially U-shape.

15. The toothbrush of claim 10, wherein the lateral support members enable the bristles of the plurality of tufts to contact one another at a point in the cavity below the 25 brush face.

16. The toothbrush of claim 10, wherein said attachment means forms a substantially uniform continuous layer of bristles extending from the brush face.

17. The toothbrush of claim 10, wherein the lateral support member has a non flat top surface. 30

18. The toothbrush of claim 10, wherein the lateral support walls are curved.

19. The toothbrush of claim 10, wherein the lateral support member extends to a predetermined height between the top edge of the attachment means and a top surface of said brush face. WO 2005/032302 PCT/US2004/032463 12

20. - A lateral support member for holding bristles in a toothbrush comprising: a substantially U-shaped formation formed in a cavity of the toothbrush, at least one leg of the U-shaped formation extending to a point between a bottom edge of a staple and a brush face of the toothbrush securing the bristles to the toothbrush.