Title:
Manual toothbrush with movable head
Kind Code:
A1


Abstract:
A manual toothbrush including a handle that reciprocates into and out of a channel within a head of the toothbrush. The head includes a plurality of fixed first bristles and a first movable base that has a plurality of second bristles extending outwardly therefrom. A first end of the handle is non-releasably connected to the first movable base within the channel in the head. The first movable base is mounted for arcuate movement in response to the reciprocation of the handle when the first and second bristles frictionally engage the teeth of the user.



Inventors:
Denney, Christopher (Burlington, CA)
Dickie, Robert G. (King City, CA)
Application Number:
11/592908
Publication Date:
05/08/2008
Filing Date:
11/03/2006
Assignee:
Christopher Denney (Burlington, CA)
Primary Class:
International Classes:
A46B13/08
View Patent Images:
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Primary Examiner:
SPISICH, MARK
Attorney, Agent or Firm:
SAND, SEBOLT & WERNOW CO., LPA (CANTON, OH, US)
Claims:
1. A manual toothbrush comprising: a longitudinally elongated handle that has a gripping end; a first end and a longitudinal axis running through the gripping end and first end; a head having an outer wall and an internal channel into which the first end of the handle is slidingly received; said first end of the handle being adapted to reciprocate into and out of said channel during the brushing motion; a plurality of first bristles fixedly mounted to the outer wall of the head and extending outwardly away therefrom; a first movable base rotatably mounted on the head; said first movable base being fixedly secured to the first end of the handle such that the handle extends over the first movable base; and wherein the first movable base is arcuately movable relative to the outer wall of the head in response to the reciprocal motion of the handle; a plurality of second bristles mounted on the first movable base and extending outwardly away therefrom.

2. The manual toothbrush as defined in claim 1; wherein the outer wall of the head defines at least one aperture therein, and wherein at least a portion of said first movable base is received through said aperture.

3. The manual toothbrush as defined in claim 2, wherein the first movable base has an internal surface and an external surface; and the plurality of second bristles extend outwardly from the external surface thereof; and wherein at least one first drive pin extends outwardly away from the internal surface of the first movable base and into the channel of the head.

4. The manual toothbrush as defined in claim 3, wherein the first movable base includes side edges that extend between the internal and external surfaces thereof; and wherein the first drive pin is provided proximate a first side edge on the first movable base; whereby the first drive pin acts as a pivot point for the first movable base.

5. The manual toothbrush as defined in claim 4, further comprising a second drive pin provided proximate a second side edge on the first movable base, and wherein the first end of the handle is positioned over the first movable base and between the first and second drive pins.

6. The manual toothbrush as defined in claim 4, wherein the first end of the handle includes a first pair of gripping fingers that non-releasably engage the first drive pin on the first movable base.

7. The manual toothbrush as defined in claim 6, further comprising a second movable base mounted within a second aperture on the outer wall of the head; said second movable base being fixedly secured to the first end of the handle a spaced distance from the first movable base; and wherein the second movable base is arcuately movable relative to the outer wall of the head in response to the reciprocal motion of the handle; and wherein the second movable base includes a second plurality of second bristles mounted thereon and extending outwardly away therefrom

8. The manual toothbrush as defined in claim 7, further comprising a second drive pin extending outwardly away from an internal surface of the second movable base and into the channel of the head; and wherein the first end of the handle includes a second pair of gripping fingers that extend outwardly away from the first end of the handle in an opposite direction to the first pair of gripping fingers; and said second pair of gripping fingers non-releasably engage the second drive pin.

9. The manual toothbrush as defined in claim 6, wherein the first movable base is substantially rectangular in shape and the external surface of the first movable base includes a generally diamond shaped region that extends through the aperture and engages a portion of the outer wall when the first movable base pivots in response to reciprocal motion of the handle; and wherein the second bristles extend forwardly away from the diamond shaped region.

10. The manual toothbrush as defined in claim 6, wherein the first movable base is substantially circular in shape and the aperture in the outer wall of the head is substantially circular in shape; and the first movable base rotates about a central point within the circular aperture.

11. The manual toothbrush as defined in claim 1, wherein the head comprises: a front cover; said outer wall of the head constituting a part of said front cover; a back cover that is complementary shaped to the front cover and is securable thereto; said front cover and back cover defining the internal channel of the head therebetween.

12. The manual toothbrush as defined in claim 11, further comprising: a bristle assembly that includes a skirt which is securable over the outer wall of the front cover; and wherein said first bristles are integrally formed with the skirt and extend outwardly away therefrom.

13. The manual toothbrush as defined in claim 11, wherein the front cover is molded with at least one recess in a rear surface of the outer wall; and said aperture opens into said recess; and wherein said first movable base is seated within said recess.

14. The manual toothbrush as defined in claim 13, wherein the channel extends through the recess and the rear surface of the outer wall is provided with a shoulder that limits the travel of the first end of the handle within the channel.

15. The manual toothbrush as defined in claim 1, wherein the arcuate motion of the first movable base is activated by the frictional engagement of the first and second bristles with the teeth of an individual as the handle is reciprocated along a longitudinal axis thereof.

16. A manual toothbrush comprising: a longitudinally elongated handle that has a gripping end; a first end and a longitudinal axis running through the gripping end and first end; a first pair of gripping fingers extending outwardly away from said first end of the handle; a head having an outer wall and an internal channel into which the first end of the handle is slidingly received; said first end of the handle being adapted to reciprocate into and out of said channel during the brushing motion; a plurality of first bristles fixedly mounted to the outer wall of the head and extending outwardly away therefrom; a first movable base rotatably mounted on the head; said first movable base having an interior surface that extends into the channel; a first drive pin extending outwardly away from the interior surface of the first movable base and into the channel; said first drive pin being non-releasably captured by the first pair of gripping fingers; whereby the first movable base is arcuately movable relative to the outer wall of the head in response to reciprocation of the handle during brushing; a plurality of second bristles mounted on an exterior surface of the first movable base and extending outwardly away from the outer wall of the head; whereby the arcuate movement of the first movable base during brushing causes the second bristles to move arcuately relative to the outer wall of the head.

17. The manual toothbrush as defined in claim 16, wherein the gripping end and first end of the handle are unitary.

18. The manual toothbrush as defined in claim 17, wherein the gripping end of the handle terminates in a leading end; and wherein the first end of the handle originates at the leading end of the collar.

19. The manual toothbrush as defined in claim 16, wherein the first pair of gripping fingers are immovable relative to the first end of the handle.

20. The manual toothbrush as defined in claim 16, wherein the first pair of gripping fingers extends outwardly at an angle from a first side edge of the first end of the handle; and that angle remains constant during reciprocation of the handle.

21. The manual toothbrush as defined in claim 20, wherein the angle of the gripping fingers relative to the first side end of first end of the handle is ninety degrees.

22. The manual toothbrush as defined in claim 16, further comprising: a second pair of gripping fingers extending outwardly away from said first end of the handle and a spaced distance away from the first pair of gripping fingers; a second movable base rotatably mounted on the head; said second movable base having an interior surface that extends into the channel; a second drive pin extending outwardly away from the interior surface of the second movable base and into the channel; said second drive pin being non-releasably captured by the second pair of gripping fingers; whereby the second movable base is arcuately movable relative to the outer wall of the head in response to reciprocation of the handle during brushing; a second plurality of second bristles mounted on an exterior surface of the second movable base and extending outwardly away from the outer wall of the head; whereby the arcuate movement of the second movable base during brushing causes the second plurality of second bristles to move arcuately relative to the outer wall of the head.

23. The manual toothbrush as defined in claim 22, wherein the second pair of gripping fingers extend outwardly away from a second side edge of the first end of the handle and at a fixed angle thereto; whereby the first and second movable bases oscillate in opposite directions to each other upon reciprocation of the handle during brushing.

Description:

BACKGROUND OF THE INVENTION

1. Technical Field

This invention generally relates to oral implements. More particularly, the invention relates to a toothbrush. Specifically, the invention relates to a manual toothbrush having a handle that reciprocates within a channel formed in the head of the toothbrush and thereby causes arcuate movement of some of the bristles on the toothbrush head.

2. Background Information

Many people brush their teeth with a manually operated toothbrush. These brushes are ideally used by positioning the bristles at a 45-degree angle to the gum line and applying a reciprocating back and forth motion to cause the tips of the bristles to move over the surfaces of the teeth. This motion causes the bristle tips to travel across the surface of the teeth in a substantially linear fashion and to remove plaque and particulate material as they do so.

Many dentists, however, believe that moving the tips of the bristles in a rotary motion over the surface of the teeth is far better for removing plaque and particulate material from the teeth. This may be achieved by moving the entire toothbrush head in a rotating or oscillating fashion across the teeth or by rotating or oscillating the bristles.

The prior art includes a number of powered and manual toothbrushes that incorporate a rotary motion of some or all of their bristles. For instance, U.S. Pat. No. 1,557,244, issued to Domingue discloses a manual toothbrush that has a handle that reciprocates in and out of the head of the brush. The interior walls of the handle are provided with a rack, while the head is provided with a number of independently rotatable brushes, each of which is provided with a toothed pinion. The toothbrush is used by holding the head of the brush stationary with one hand and then reciprocating the handle back and forth within the head. The rack and pinion mechanism causes the brushes to rotate.

U.S. Pat. No. 5,068,939 to Holland, discloses a manual toothbrush comprising an integrally formed handle and head. The head is provided with a plurality of individually rotatable or oscillating bristle clusters. Each cluster of bristles includes a crank mechanism for connecting the cluster to a rod that extends through the interior of the head and handle of the toothbrush. The rod is operationally geared to a weight in the handle. As the toothbrush is reciprocated, the weight travels back and forth within the handle, causing the gears to rotate and thereby causing the rod to reciprocate within the interior of the handle and head. The reciprocating rod rotates the individual bristle clusters within the head.

U.S. Pat. No. 5,186,627, issued to Amit et al, discloses a manual toothbrush that has base with a plurality of fixed bristles and one rotatable member that also includes a set of bristles. The base is positioned over a front portion of the handle and a cover is provided around the sides of the base and front portion. The front portion of the handle includes a toothed rack and the lowermost surface of the rotatable member includes a pinion. The cover and base are longer than the front portion of the handle. Consequently, as the handle is moved back and forth during brushing, the front portion of the handle moves back and forth within the cover and the interlocking rack and pinion forces the rotatable member on the base to rotate.

U.S. Pat. No. 5,274,870 issued to Stollman also discloses a toothbrush having an integrally formed head and handle. The head includes a frame having a cavity therein and in which a carriage travels back and forth. The frame is also provided with a toothed rack. The carriage is provided with a plurality of bristles thereon, and a number of those bristles have gears provided at their lower ends. As the carriage slides within the frame during brushing, the rack engages the gears causing the geared bristles to rotate.

Finally, U.S. Pat. No. 5,276,932 issued to Byrd discloses a toothbrush including one or more rotatable bristle members that are geared to a thumb-actuated member. As the thumb-actuated member is engaged in a first direction, the rotatable bristles rotate in a first direction. When the thumb-actuated member is engaged in a second direction, the rotatable bristles rotate in a second direction.

The devices disclosed in the prior art have a variety of different mechanisms for causing rotation of some of the bristles in the head. In every instance mentioned above, however, the mechanism has required some form of geared interaction between the various components. The geared mechanisms are reasonably complicated and therefore relatively more expensive to manufacture. There is therefore still a need in the art for a manually operable toothbrush that imparts both linear and rotational motion to bristles mounted on its head without the use of gears and which effectively clears plaque and particulate material from the surface of the teeth.

SUMMARY OF THE INVENTION

The device of the present invention comprises a manual toothbrush including a handle that reciprocates into and out of a channel within a head of the toothbrush. The head includes a plurality of fixed first bristles and a movable base that includes a plurality of second bristles extending outwardly therefrom. The movable base is mounted for arcuate movement relative to the outer surface of the head of the toothbrush. A first end of the handle is non-releasably connected to the movable base within the channel in the interior of the head. A movement of the handle in a first direction causes the movable base and therefore the second bristles to move in a first direction. Movement of the handle in the opposite direction causes the movable base and therefore the second bristles to move in a second direction. The rotational motion of the movable base is caused when the friction generated as the bristles move over the surface of the teeth is sufficiently large enough to overcome the internal friction of the moving components within the toothbrush head. If the internal friction in the toothbrush head is greater than the drag or friction experienced by the tips of the bristles, then the movable base will not oscillate or rotate. The total movement of the moving components within the brush head is very limited.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the invention, illustrative of the best mode in which applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims.

FIG. 1 is a front elevational view of a first embodiment of a toothbrush in accordance with the present invention;

FIG. 2 is a side elevational view of the toothbrush of FIG. 1;

FIG. 3 is an exploded front perspective view of the toothbrush in accordance with the present invention;

FIG. 3A is an enlarged perspective view of the exploded head of the toothbrush shown in FIG. 3;

FIG. 3B is a front view of the movable base;

FIG. 4 is an exploded rear perspective view of the toothbrush in accordance with the present invention;

FIG. 4A is an enlarged perspective view of the exploded head of the toothbrush shown in FIG. 4;

FIG. 4B is a rear view of the movable base;

FIG. 5 is an enlarged rear perspective view of the toothbrush;

FIG. 6 is a rear view of the toothbrush with the cover removed with the movable heads in a first position;

FIG. 6B is a front view of the toothbrush with the front cover and bristle assembly removed to more clearly show the positioning of the movable heads relative to the extension of the shaft;

FIG. 7 is a rear view of the toothbrush with the cover removed with heads in a second position; and

FIG. 8 is a front view of a second embodiment of a toothbrush in accordance with the present invention; and

FIG. 9 is a rear view of the toothbrush of FIG. 8, with the back cover removed.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-5, there is shown a toothbrush in accordance with the present invention and generally indicated at 10. Toothbrush 10 includes a handle 12 and head 14. Head 14 includes a plurality of bristles 16 thereon for removing plaque and particulate matter from the surface of the teeth (not shown) of a user. A first plurality of said bristles 16 are fixed in place on the head and a second plurality of bristles 16 are arcuately movable as will be hereinafter described.

Handle 12 is ergonomically designed to enable the toothbrush 10 to be easily held and manipulated. Handle 12 comprises a gripping section 18 and a first end that extends outwardly away therefrom. First end comprises an actuating shaft 20 that is fixed to gripping section 18 and extends outwardly away therefrom. Shaft 20 further includes an extension 22 that is both thinner and narrower than shaft 20. Extension 22 is also fixedly mounted to shaft 20, thus, gripping section 18, shaft 20 and extension 22 all move together as a single unit when toothbrush 10 is moved back and forth across the teeth. Handle 12 is therefore a longitudinally elongated member that has a longitudinal axis “X” (FIG. 1). During use, toothbrush 10 is reciprocated along the longitudinal axis “X” thereof.

In accordance with one of the specific features of the present invention, extension 22 includes two spaced apart pairs of gripping fingers 24, 26 that extend laterally outwardly away from the sides 22a, 22b of extension 22. The first pair of fingers 24 extends laterally outwardly away from the side 22a of shaft extension 22 in a first direction, while the second pair of fingers 26 extends outwardly away from the side 22b of shaft extension 22 in a second direction (FIG. 4). The two fingers of the first pair of fingers 24 are separated from each other by a small gap. Similarly, the two fingers of the second pair of fingers 26 are also separated from each other by a small gap. Both the first pair and second pair of fingers 24, 26 are fixed in position on extension 22, i.e., the fingers are immovable relative to the extension 22. Furthermore, the angle between the fingers of each of the first and second pair of fingers 24, 26 relative to extension 22 remains constant. That angle preferably is ninety degrees to the longitudinal axis “X” of handle 12. The purpose of these fingers 24, 26 will be hereinafter described.

Head 14 of toothbrush 10 is shown in detail in FIGS. 3-5. Head 14 preferably is generally spoon-shaped and comprises a back cover 28 and a complementary shaped front cover 30. Back and front covers 28, 30 are designed to snap-fit together or to be otherwise fixedly secured to each other. Both back and front cover 28, 30 include a rounded end portion 28a, 30a and a narrower shank portion 28b, 30b. Back cover 28 may also include one or more apertures 32 therein.

Front cover 30 is formed so as to include two spaced apart recesses 34, 36 in the inner surface 30c thereof (FIGS. 4 & 5). Recesses 34, 36 open up in apertures 38, 40, respectively, in outer surface 30d of front cover 30. Apertures 38, 40 are smaller than recesses 34, 36. Front cover 30 also includes a channel 42 in its inner surface 30c that extends from the end of shank portion 30b to recess 34. Channel 42 includes a first section that is shaped and sized to receive shaft 20 of handle 12 therein and a second section that is shaped and sized to receive extension 22 therein. A shoulder 44 is provided at that portion of channel 42 where the first section thereof joins the second section thereof. Shoulder limits the travel of shaft 20 therein. Front and back covers 30, 20, snap fit together around shaft 20 and extension 22. The dimensions of front and back covers 30, 20, shaft 20 and extension 22 are such that shaft 20 and extension 22 can travel within channel 42 between a first position (FIG. 1) where the end 46 of head 14 abuts a leading end 48 of gripping section 18; and a second position (FIG. 2) where a gap exists between end 46 of head 14 and leading end 48 of gripping section 18.

Head 14 further includes a bristle assembly 50 and two movable bases 52, 54. Bristle assembly 50 comprises a flexible skirt 56 with a plurality of bristle tufts 58 extending outwardly away therefrom. These bristles 58 constitute the fixed, nonmovable bristles 16 of head 14. The layout, number and relative sizes of said bristles 58 can be of any desired configuration without departing from the spirit of the present invention. Skirt 56 is designed to snap fit around outer surface 30d of front cover 30 and a lip 59 (FIG. 3) that, once passed around the appropriate region of outer surface 30d, becomes locked between front and back covers 30, 20 when they are secured together. Skirt 56 could, alternatively be glued to outer surface 30d. Skirt 56 also includes two apertures 56a (FIG. 1) which are shaped and positioned to align with the apertures 38, 40 in front cover 30. It will be understood that while the preferred embodiment of the invention includes a bristle assembly 50 that, alternatively, a plurality of bristle tufts may be individually adhesively secured into front cover 30 in any designed pattern or configuration.

Referring to FIGS. 3A-4B, 6 &7, head 14 is provided with two movable bases 52, 54 that are designed to arcuately move in response to a combination of the reciprocation of handle 12 and the frictional engagement of bristles 16 with the surface of the user's teeth. Movable bases 52, 54 are substantially identical. The following description therefore is made with reference to movable base 52, but it will be understood that it applies equally to movable base 54. Movable base 52 comprises a generally rectangular member 60 that is formed with a narrower saddle region 62 in the middle of the rectangular member 60 and a pair of rounded outside ends 64, 66. Member 60 includes an interior surface 60a (FIG. 4A) and an exterior surface 60b (FIG. 3A). Interior surface 60a of member 60 includes pair of spaced apart drive pins 68, 70 that extend outwardly away therefrom. Drive pins 68, 70 are positioned proximate ends 66 and 64, respectively and toward the peripheral outer edge 65 of member 60. Extension 22 extends over the rear surface 60a of member 60 and over the saddle region 62 thereof, and intermediate drive pins 68, 70. In this first embodiment of the invention, each of the movable bases 52, 54 have a side pivot point and a side drive pin location. In the instance of movable base 52, extension 22 is connected to drive pivot 68 and base 52 pivots about drive pin 70.

The exterior surface 60b of member 60 includes a shaped, and preferably diamond-shaped, region 72 that extends outwardly away therefrom. Region 72 is formed inwardly of the outer edge 65 of member 60. A plurality of fixed bristles or bristle tufts 74 extend outwardly away from region 72. The number, size and configuration of bristles 74 can be of any suitable desired design without departing from the spirit of the present invention. Region 72 at least partially abuts that portion of the wall of front cover 30 that surrounds and defines apertures 38, 40. The arcuate travel of mounting bases 52, 54 is at least partially guided by the interaction between region 72 and the edges 39, 41 (FIG. 3A) of front cover 30 surrounding apertures 38, 40.

In accordance with one of the features of the present invention, member 60 is sized to be received within recess 34 of front cover 30, but as shown in FIG. 6 the recess 34 is larger than member 60 and, consequently, member 60 can be moved within recess 34, as hereinafter described. At the same time, the hole 38 in front cover 30 is smaller than exterior surface 60b of member 60, but larger than region 72 on member 60. Thus, movable base 52 is inserted into recess 34 so that region 72 and bristles 74 project outwardly away from front surface 30d of front cover 30 and exterior surface 60b of base 52 abuts the interior surface 30c of front cover 30. Similarly, movable base 54 is inserted into recess 36 and a similar region 72a and bristles 74a project outwardly away from front surface 30d of front cover 30.

Referring to FIGS. 6 & 7, toothbrush 10 is assembled and used as follows. Bristle assembly 50 is placed over front surface 30d of front cover 30. Movable bases 52, 54 are inserted into recesses 34, 36 so that bristles 74 and 74a extend outwardly through holes 38, 40 and away from front surface 30d of front cover 30. Handle 12 is then connected into the inner surface 30c of front cover 30 by placing extension 22 and shaft 20 into channel 42. Fingers 24 engage and lock around drive pin 68 on movable base 54 and fingers 26 engage and lock around drive pin 70 on movable base 52. Obviously, it would also be possible that fingers 24 could engage and lock around drive pin 70 on movable base 52 and fingers 26 engage and lock around drive pin 62 on movable back 54, instead. Once fingers 24 and 26 are engaged with the respective drive pins 70, 68, they do not release the drive pins 70, 68, but rather stay substantially permanently connected thereto. FIGS. 6 & 7 show that extension 22 extends over the middle of each of the movable bases 52, 54 as opposed to being positioned alongside one of side edges 65 thereof. Back cover 28 is then snap fitted over inner surface 30c of front cover 30, thereby securing back and front covers 28, 30 together and securing bristle assembly 50 in place. Toothbrush 10 is now ready for use.

Toothbrush 10 is positioned in the mouth of the use so that the tips of bristles 74 and 58 engage the surface of the teeth, preferably at 45 degrees to the gum line. The brush 10 may start out in the first position shown in FIG. 6 and then be reciprocated into the second position shown in FIG. 7, and then back to the first position again, or vice versa. In the first position, the end 46 of head 14 is in abutting contact with the leading end 48 of handle 12. It should be noted that when brush 10 is in this first position, leading end 20a of shaft 20 is spaced a distance away from shoulder 44 of front cover 30 and leading end 22a of extension 22 is a spaced distance away from end 42a of channel 42. It should also be noted that the orientation of movable base 52 within recess 34 is opposite to the orientation of movable base 54 in recess 36, i.e., the end 66a of movable base 52 lies closer to the tip 80 of toothbrush 10 than does the end 64a thereof; while the end 66b of movable base 54 lies further from tip 80 than does the end 64b thereof.

When handle 12 of toothbrush 10 is pulled in the direction of arrow “A” (FIG. 6), friction between the tips of bristles 74 and 58 and the surface of the teeth tends to want to keep the bristles 74 and 58 substantially stationary. At the same time, the shaft 20 and extension 22 want to move in the direction of arrow “A” with gripping section 18 of handle 12. When the movement of the shaft 20 and extension 22 overcomes the friction between the bristles 58 and the teeth, then movable bases 52, 54 are forced to rotate within recessed 38, 40 in the direction indicated by arrows “B” and “C”, respectively. This occurs because fingers 26, 24 are non-releasably engaged with drive pins 70, 68 and the fingers 26, 24 are being pulled in the direction of arrow “A” by extension 22. The rotation of movable bases 52, 54 causes bristles 74, 74a to rotate relative to outer surface 30d of front cover 30 and to inscribe an arc across the surface of the teeth of the user. At the same time, fixed bristles 58 move linearly across the surface of the teeth in the direction of arrow “A”.

When handle 12 is pulled in the direction of arrow “A” and head 14 initially remains essentially stationary, a gap opens up between end 46 of head 14 and leading end 48 of handle 12. This gap is illustrated at 82 in FIG. 7. It will also be noted that the distance between shoulder 44 and leading end 20a of shaft 20 increases, as does the distance between leading end 22a of extension 22 and end 42a of channel 42.

The handle 12 of toothbrush 10 is then pushed in the opposite direction as indicated by arrow “D” (FIG. 7). Because the tips of bristles 74 and 58 are in contact with the surface of the teeth, friction between the tips and the surface causes head 14 to substantially remain in place while handle 12 slides inwardly along channel 42 and into head 14. This inward movement causes drive pin 68 on movable base 54 to be moved closer to tip 80, thus causing a rotation “E” in movable base 54. The inward movement also causes drive pin 70 on movable base 52 to move closer to tip 80, thereby causing a rotation “F” in movable base 52. Furthermore, leading end 20a of shaft 20 moves into abutting contact with shoulder 44 and leading end 22a of extension 22 moves into abutting contact with end 42a of channel 42. The rotation of movable bases 52, 54 causes the tips of bristles 74 to inscribe an arc across the surface of the teeth. At the same time, the tips of bristles 58 travel linearly across the surface of the teeth in the direction of arrow “D”.

Thus, as the handle 12 is moved reciprocally back and forth along the longitudinal axis “X” of toothbrush 10 between direction “A” and “D”, the movable bases 52 and 54 and therefore the bristles 74 extending outwardly therefrom are caused to oscillate reciprocally between the position shown in FIG. 6 and the position shown in FIG. 7. At the same time, the bristles 58 are moving in a linear fashion across the teeth parallel to the longitudinal axis “X” of the toothbrush 10.

Toothbrush 10 therefore includes a first plurality of fixed bristles that move reciprocally across the teeth in a linear fashion and a second plurality of bristles that are moved reciprocally across the teeth in an arcuate fashion. The arcuate motion of the second plurality of bristles is caused by the reciprocal motion of the handle in conjunction with the friction of the tips of the bristles on the surface of the teeth.

FIGS. 8 & 9, show a second embodiment of a toothbrush in accordance with the present invention and generally indicated at 110. Toothbrush 110 includes substantially all of the same features as toothbrush 10 with the exception that the movable bases 152 and 154 are substantially circular in shape. Movable bases 152, 154 are received within circular recesses 134, 136 in front cover 130. The fingers 124, 126 on extension 122 are non-releasably engaged with drive pins 168, 170. Drive pins 168, 170 are positioned proximate the peripheral outer edge 190, 192 of movable bases 152, 154. Movable bases 152, 154 are caused to move in a substantially circular motion around a central pivot point by shaft 120 and extension 122 as handle 112 is reciprocated back and forth along the longitudinal axis “Y” of toothbrush 110. Movable bases 152 and 154 therefore effectively have a center pivot in that they rotate within recesses 134, 136, but have a side drive pin 168, 170. The effective difference between the two embodiments is that, with the same input movement of the handle 12 or 112, the circularly shaped movable bases 152, 154 will experience more arcuate or circular movement than do the rectangular movable bases 52 and 54 of toothbrush 10.

While the above disclosure has shown two movable bases 52, 54 that move arcuately in opposite directions to each other during reciprocation of the handle, it will be understood that the first and second pairs of gripping fingers 24, 26 could be provided a spaced distance apart on the same side of the extension 22. This would cause the two movable bases 52, 54 to rotate or oscillate in the same direction as each other.

In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.

Moreover, the description and illustration of the invention are an example and the invention is not limited to the exact details shown or described.