TOOTHBRUSH AND MANUFACTURING METHOD THEREOF
A toothbrush includes a head and a plurality of bristles. Each bristle includes a first end exposed outside the head of the toothbrush, and a second, opposite end being placed in the head of the toothbrush. The second ends of the bristles are fused together, in bundles, to be thermally attached directly to the head of the toothbrush and/or to define a continuous layer in which at least some of the bundles are also fused together.
This application is a continuation in part of U.S. Ser. No. 11/586,631, filed on Oct. 26, 2006 which is a divisional of U.S. Ser. No. 10/627,913, filed on Jul. 28, 2003 which, in turn, is based on and claims priority from Korean Patent Application No. 2002-76349 filed on Dec. 3, 2002. The above listed applications, in their entirety, are incorporated herein by reference.
BACKGROUND1. Technical Field
The present disclosure relates generally to a toothbrush and a manufacturing method thereof.
2. Description of the Related Art
Since the introduction of a toothbrush tufted with tapered bristles for effective plaque removal and prevention of damage to gums during teeth brushing, its verified effectiveness has recently made this toothbrush popular.
For fabrication of such a traditional toothbrush, 28 to 33 mm long bristles, which are needle-shaped on one end t and non-needle-shaped on the other end n, are folded over such that the needle-shaped portion is longer than the non-needle-shaped portion, as illustrated in
As illustrated in
In Korea Patent No. 311360, the present inventor disclosed a toothbrush tufted with ordinary bristles tapered on both ends and at least one 1 to 10 mm longer bristle 62 of the same shape.
The above techniques, though they have their own benefits and drawbacks, commonly boast excellent plaque removal and improved health of gums.
The following shortcomings are observed by the present inventor(s) in terms of one or more of complex manufacturing, high inferior goods rate, and thus high production cost, for the following reasons.
(1) In order to shape ordinary polyester bristles into needles, the tips of the bristles are treated with a chemical such as caustic soda or sulphuric acid. During this process, the total length and tapered length of the bristles are difficult to control, thereby resulting in many inferior bristles. (2) In the case of a today's popular needle-shaped toothbrush tufted with bristles tapered on both ends, both tips of the bristles are treated in the above-described manner, for needle shaping. Even if one tip of a bristle is successfully tapered, the failure of the other tip leads to the whole failure of the bristle. (3) There are no appropriate applications for utilizing bristles having wrong lengths.
Besides, the traditional toothbrush bristles are planted in simple patterns and not tightly fixed, as illustrated in
Several exemplary embodiments of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:
Several exemplary embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail for the sake of simplicity.
As used herein, two originally separate elements are “thermally fused” or “thermally fused together” or “fused together” or “fused” when they are joined by melted and then solidified materials (including but not limited to plastics, especially polyester) of both elements. The term “fusion” or “thermal fusion” or “fused portion” means a structure resulted from several elements being fused together.
As used herein, two originally separate elements are “thermally attached” when a melted material (including but not limited to plastics, especially polyester) of at least one element adhered to the other element and then solidified. The term “thermal attachment” means a structure resulted from several elements being thermally attached with each other. Accordingly, the term “thermally attached” and “thermal attachment” cover “thermally fused” and “fused portion” respectively.
A toothbrush according to one or more embodiments of the present invention is comprised of one-end tapered bristles formed of polyester resin to be 13 to 18 mm in total length and 4 to 8 mm in tapered length. To manufacture the toothbrush, the non-tapered portions of the bristles are pushed down into through holes arranged in a planting pattern in a bristle holder. Portions of the bristles protruding beyond the bottom of the bristle holder are thermally fused to thereby fix, at least temporarily, the bristles to the bristle holder. The bristle holder is then attached to the head of the toothbrush.
Since the bristle 60 is planted 5 to 6 mm deep in a toothbrush head, it is then 7 to 13 mm high from the surface of the toothbrush head.
The tapered tip of the bristle 60 is 0.01 to 0.08 mm thick. The tapered tip thickness is preferably 0.01 to 0.03 mm to allow the bristles to reach deep between teeth and into gum pockets, and 0.03 to 0.08 mm for thorough cleansing. Both features can be obtained by planting the two types of bristles in combination, or grinding bristles by means of a mesh paper (i.e. sandpaper) after planting, which will be described later.
In some embodiments, it is preferable to form the bristles of polyester resin, specifically PET (Polyethylene Terephthalate) or PBT (Polybuthylene Terephthalate) resin. Other materials, such as Nylon, acryl, and PP (Polypropylene) resin, are not excluded and may be used in other embodiments (especially where non-tapered bristles are used), although such materials are inferior in terms of water resistance, durability, and strength, and bristles formed of such a material may be entangled when they are immersed in a strong acid or alkaline solution, for tapering, resulting in difficult processing.
Since the primary and secondary bristle holders 20 and 30 function to transfer the bristles 60 to the head insert 50, they are of a metal due to its excellent durability. The head insert 50 is formed of plastic because it is attached to a toothbrush body 70, with the bristles 60 planted therein.
The bristles 60 are held in the primary bristle holder 20 by pushing the bristles 60 into the primary bristle holder 20 with a pusher 40 having inserting poles 41 matching the through holes 21 of the primary bristle holder 20, as illustrated in
Referring to
Referring to
In some embodiments, a portion of the head insert 50 is also thermally fused into one or more fused portions 135 of the bristles 60. That is, while the bristles 60 protruding from the head insert 50 are being melted, the adjacent portion of the head insert 50 is also melted, at least partially. Upon solidification, the at least partially melted adjacent portion of the head insert 50 and the melted portions of the bristles 60 together form a common fused portion.
In some embodiments, one or more fused portions 135 bristles 60 and an adjacent portion of the head insert 50 are thermally attached to each other. That is, while the bristles 60 protruding from the head insert 50 are being melted, the adjacent portion of the head insert 50 is not melted. Upon solidification, the melted portions of the bristles 60 together form a fused portion 135 which, while still in the melted or soften state, adheres to the adjacent portion of the head insert 50 to form a thermal attachment with the head insert 50.
Whether or not the bristles 60 and the head insert 50 are fused together or are thermally attached depend on the respective materials of the bristles 60 and head insert 50 as well as on the conditions, such as temperature, duration, pressure, etc., in the process disclosed above with respect to
During the process disclosed above, the length of the bristles 60 is controllable to some extent. That is, short bristles 60 are thermally fused while they are protruded to a short length, for example, 1 mm or less, and long bristles 60, while they are protruded to a long length, for example, about 3 mm. In the case of very long bristles, they are thermally fused in the above manner and then their tips are cut, followed by grinding with a mesh paper. Therefore, an available length range for the one-end tapered bristles 60 is widened.
When the bristles differ in length after planting, the tips of longer ones are cut and ground by a mesh paper. Thus, the length and tip thickness of the bristles are controlled. In this case, bristles having a tip thickness of 0.01 to 0.03 mm coexist with ones having a tip thickness of 0.03 to 0.08 mm. As a result, the bristles reach deeper between teeth and into gum pockets and clean the surfaces of the teeth thoroughly.
To reach deeper into the gum pockets, the bristles can be planted such that they differ in length by 1 to 10 mm. That is, the planting of long bristles and short bristles with a 1 to 10 mm length difference makes the longer ones reach further between teeth or into gum pockets.
The head insert 50 having the bristles 60 fixed thereto is attached to the head of the toothbrush body 70 by one or more of adhesive, mechanical engagement, ultrasonic bonding or high frequency bonding.
Considering product yield, the ultrasonic or high frequency boding is more preferable. In this case, a head insert opening 51 is preferably formed in the head of the toothbrush body 70, so that the head insert 50 can be mounted in the head insert opening 51, as illustrated in
An alternative way of fixing the head insert 50 with the bristles 60 to the toothbrush body 70 is, as illustrated in
Another way of planting the bristles 60 in a toothbrush body is that the non-tapered portions of the bristles 60 are inserted into through holes in the lower metal mold 90, protruding 2 to 5 mm from the metal mold 90, these protrusions are thermally fused, an upper metal mold (not shown) is combined with the lower metal mold 90, and then resin is injected so that the bristles 60 are attached directly to the toothbrush body, as illustrated in
In some embodiments, the bristles 60 protruding from the head insert 50 are thermally fused into fused portions 135 as exemplarily illustrated in
As exemplarily illustrated in
The formation of the continuous layer 136 depends on various factors, including but not limited to, the fusion conditions, the length and material property of the protruding portions of the bristles 60, the density (i.e., number of holes per unit area) of the through holes in the head insert 50 etc. By varying one or more of the disclosed and/or any other factors, the number, position, size, shape, thickness etc. of the continuous layer 136 can be varied, resulting in various cleaning effects of the toothbrush.
In some embodiments, the bristles in the fused portions 135 and continuous layer 136 no longer retain their original shapes and cannot be separated from each other. In some embodiments, the thermal attachment of the fused portions 135 and continuous layer 136 with the head insert 50 may be broken, resulting in potential slight movements of the bundles relative to the head. Such potential slight movements, if indeed exist, are greatly limited by the manner the bundles are joined together by the continuous layer 136 (especially in the embodiment disclosed with respect to
It should be noted that since thermal attachment or fusion is used for fixing the bristles 60 to the head insert 50, the bundles of the bristles 60 is easily configurable to be of any shape and/or size and/or position and/or bristle density (bundle strength), thereby permitting various designs of such bundles to be made with great flexibility in size, shape, position, bristle density, not to mention length and taperness as disclosed above. The result is that cleaning effects of the toothbrush can be enhanced and/or customized as desired. An example of possible bundle configurations is given in
The above disclosed “free design” feature is hardly obtainable, if at all, with the known technique of fixing bristles 60 via folding and clipping etc. The reason is that a folded bundle generally has a symmetrical configuration about the folding line, and is difficult to fit in holes of certain sizes and shapes (such as 195, 196 in
In contrast, in embodiments of the instant application, simply by varying sizes, shapes, positions of the through holes 21, bundles of corresponding configurations are easily obtainable with numerous advantages discussed herein, e.g., enhanced plaque removal effects and/or aesthetic appearance (when bundles of multiple colors and/or shapes are included).
The structures disclosed above with respect to
As described above, the toothbrush according to one or more embodiments of the present invention is tufted with needle-shaped bristles tapered only on one end, as compared to the traditional toothbrush having both-end tapered bristles. Therefore, an inferior goods rate is remarkably dropped and thus product cost can be reduced by 30% or more.
However, it is within the scope of the present invention to provide toothbrushes that, according to some other embodiments, are tufted with bristles that are not tapered at either end. Toothbrushes according to further embodiments of the present invention are tufted with a mix of one-end-tapered bristles and non-tapered bristles.
Furthermore, a bristle planting pattern and the number of the needle-shaped bristles can be freely controlled, thereby enabling the bristles to clean away hard-to-reach plague. The use of thermal fusion instead of a cut wire leads to tighter fixing of the bristles. Even needle-shaped bristles which are failed in length control can be utilized for fabrication of the toothbrush.
Thus, one or more embodiments provide a toothbrush tufted with needle-shaped and/or non-tapered bristles, which is manufactured in a simplified process at a diminished failure rate.
One or more embodiments provide a method of utilizing bristles having wrong lengths for manufacture of a toothbrush.
One or more embodiments provide a method of fixing bristles more tightly in a toothbrush.
One or more embodiments provide a method of freely designing a bristle planting pattern and adjusting the number of bristles for a toothbrush.
While exemplary embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims
1. A toothbrush, comprising:
- a head; and
- a plurality of bristles, each of said bristles comprising a tapered first end exposed outside the head of the toothbrush, and a second, opposite end being placed in the head of the toothbrush,
- wherein the second ends of the bristles are fused together, in bundles, to be thermally attached directly to the head of the toothbrush.
2. The toothbrush of claim 1, wherein
- the head of the toothbrush further comprises a head insert which comprises opposite first and second surfaces, and a plurality of through holes extending from the first surface to the second surface of said head insert; and
- each of said bundles comprises several said bristles received in one of the through holes, with the respective second ends of the bristles protruding beyond the second surface of the head insert and defining a fused portion which is larger than a diameter of the respective through hole and which is thermally attached to the head insert.
3. The toothbrush of claim 2, wherein
- several of said bundles are fused together at the respective fused portions to define a continuous layer that extends across the respective through holes in which said several bundles are received.
4. The toothbrush of claim 3, wherein
- all of said bundles are fused together at the respective fused portions to define a continuous layer that extends across all said through holes.
5. The toothbrush of claim 2, further comprising a handle having a head insert opening in which said head insert is mounted.
6. The toothbrush of claim 1, wherein, said bristles are polyester resin bristles.
7. The toothbrush of claim 1, wherein
- each said bristle is tapered only on said first end thereof and further comprises a first non-tapered portion positioned between the tapered first end and the head of the toothbrush; and
- in each said bristle: the tapered first end has a length of from 4 mm to 8 mm and a tip thickness of 0.01 mm to 0.08 mm; the first non-tapered portion has a thickness of 0.1 mm to 0.2 mm along a length thereof; and a total length of the first non-tapered portion and the tapered first end is from 7 mm to 13 mm.
8. The toothbrush of claim 7, wherein
- said bristles comprise first bristles and second bristles;
- in each of said first bristles, the tip thickness of the tapered first end is 0.01 to 0.03 mm; and
- in each of said second bristles, the tip thickness of the tapered first end is 0.03 to 0.08 mm.
9. The toothbrush of claim 7, wherein, in each of at least some of said bristles, the tip thickness of the tapered first end is 0.01 to 0.03 mm.
10. The toothbrush of claim 7, wherein, in each of at least some of said bristles, the tip thickness of the tapered first end is 0.03 to 0.08 mm.
11. The toothbrush of claim 7, wherein the bristles differ in length by 1 to 10 mm.
12. The toothbrush of claim 1, wherein
- each said bristle is tapered only on said first end thereof, and the tapered first end defines the entire length of the bristle that is exposed outside the head of the toothbrush; and
- in each said bristle: the tapered first end has a length of 7 mm to 8 mm and a tip thickness of 0.01 mm to 0.08 mm.
13. The toothbrush of claim 2, further comprising:
- a toothbrush body;
- wherein the fused portions of the bundles of the bristles and the head insert are molded together with the toothbrush body.
14. The toothbrush of claim 1, further comprising:
- a toothbrush body having said head;
- wherein the fused second ends of the bristles are directly molded together with the head of the toothbrush body.
15. A tooth brush made by a method comprising the steps of:
- inserting a plurality of bristles into each of a plurality of through holes defined between an upper surface and a lower surface of a head insert, said lower surface being near to a bottom of the head insert, each of said bristles defining a non-tapered portion at a first end and a tapered portion at a second end opposite to the first end thereof, said non-tapered portion being received into the through hole; and
- maintaining the tapered portions of the bristles outside and away from the upper surface of the head insert and the non-tapered portion of the bristles to protrude from the lower surface of the head insert;
- thermally fusing the non-tapered portion of the bristles protruding from the lower surface of the head insert, thereby fixing the bristles to the head insert;
- attaching the bottom of the head insert to an upper metal mold; combining the upper metal mold with a lower metal mold; and
- injecting resin into the lower metal mold through an inlet, thereby attaching the head insert to a head of the toothbrush.
16. A tooth brush made by a method comprising the steps of:
- inserting a plurality of bristles into each of a plurality of through holes defined between a top part and a bottom part of a lower metal mold, each of said bristles defining a non-tapered portion at a first end and a tapered portion at a second end opposite to the first end, said non-tapered portion being received into the through hole to protrude 2 to 5 mm from the bottom part of the lower metal mold; and
- maintaining the tapered portion of the bristles outside and away from the top part of the lower metal mold; thermally fusing the protruded non-tapered portion of the bristles;
- combining an upper metal mold with the lower metal mold; and injecting resin into the upper and lower metal molds, thereby fixing the bristles directly to a head of the toothbrush.
17. A toothbrush, comprising:
- a head; and
- a plurality of bristles, each of said bristles comprising a tapered first end exposed outside the head of the toothbrush, and a second, opposite end being placed in the head of the toothbrush,
- wherein
- the head of the toothbrush further comprises a head insert which comprises opposite first and second surfaces, and a plurality of through holes extending from the first surface to the second surface of said head insert;
- several said bristles are received in each of the through holes to form a bundles of the bristles, with the respective second ends of the bristles protruding beyond the second surface of the head insert and being fused together into a fused portion which is larger than a diameter of the respective through hole; and
- at least some of said bundles are also fused together at the respective fused portions to define a continuous layer that extends across the respective through holes in which said at least some bundles are received.
18. The toothbrush of claim 17, wherein
- all of said bundles are fused together at the respective fused portions to define a continuous layer that extends across all said through holes.
19. The toothbrush of claim 17, wherein
- the fused portions of at least some of said bundles are thermally attached to the head insert.
20. The toothbrush of claim 17, wherein
- each said bristle is tapered only on said first end thereof.
21. The toothbrush of claim 17, wherein
- each said bristle is tapered only on said first end thereof and further comprises a first non-tapered portion positioned between the tapered first end and the head of the toothbrush; and
- in each said bristle: the tapered first end has a length of from 4 mm to 8 mm and a tip thickness of 0.01 mm to 0.08 mm; the first non-tapered portion has a thickness of 0.1 mm to 0.2 mm along a length thereof; and a total length of the first non-tapered portion and the tapered first end is from 7 mm to 13 mm.
22. The toothbrush of claim 1, wherein
- said bundles have different shapes selected from the group consisting of rectangle, triangle, circle, oval, and trapezoid.
Type: Application
Filed: Jul 10, 2012
Publication Date: Nov 1, 2012
Applicant: BEST HWASUNG CO., LTD. (Paju-si)
Inventors: Young-Jun KWON (Paju), Sung-Wook KWON (Seoul)
Application Number: 13/545,660
International Classification: A46B 9/04 (20060101);