BACKGROUND OF THE INVENTION
1. Technical Field
This invention generally relates to dental hygiene. More particularly, the invention relates to a cleaning implement for teeth. Specifically, the invention relates to an electric toothbrush in which the head includes two members that are actively moved relative to each other, preferably in a direction that is substantially at right angles to the longitudinal axis of the brush.
2. Background Information
The goal of every electric powered toothbrush designer is to make a fully active powered-head toothbrush with the same size, look and feel as that of a small manual toothbrush. Some toothbrushes have been designed and manufactured to achieve this end, such as the Pulsar™ made by Procter & Gamble. These toothbrushes have a split head with a plurality of movable bristles mounted thereon. When pressure is applied to the bristles during brushing, the split portions of the head are able to be deflected independently of each other. Furthermore, these toothbrushes have a tiny, vibratory motor installed in the handle, as close to the brush head as space and styling will allow. A camshaft extends from the motor into the neck of the brush and a small, and D-shaped weight hangs off the end of the camshaft. The camshaft terminates a distance away from the head upon which the bristles are mounted. As the camshaft rotates, the weight produces a vibration that is transmitted through the neck and into head and bristles. This vibration causes the bristles to move back and forth and gives the toothbrush the appearance of having a very active head. Most of the vibration is felt in the user's hand and the vibration is not transmitted as much to the brush head itself. As soon as any pressure is applied to the ends of the bristles, such as during brushing, the vibration caused by the weight is dampened and substantially ceases.
U.S. Publication No. 2006/0272112 in the name of Braun et al and assigned to The Gillette Company, discloses a toothbrush that operates in the manner described above. The toothbrush disclosed in this publication has a split head with two portions that can move independently. The toothbrush also includes a powered mechanism for setting up a vibration in the head of the brush. The handle of the brush includes a battery and a motor and a drive shaft projects outwardly from the motor and rotates to drive an eccentrically mounted weight at the end thereof. The rotating weight sets up a vibration that is transmitted to all parts of the brush. While the head of this brush is split into two portions and the portions are able to move independently, the portions are only moved in this manner through direct pressure when the bristles contact the teeth. The vibrations produced by the weight may cause very small independent movements in the two portions, but any such movement is essentially dampened as soon as the bristles contact the teeth and pressure is applied thereto during brushing.
U.S. Pat. No. 6,564,416, issued to Claire et al and also assigned to Gillette Canada Company, discloses a manual toothbrush that has a head which is split longitudinally into two portions. The portions are angled transversely to one another and define an opening between them. The opening permits water to flow through the head to facilitate flushing away of particulate materials that have been removed from the teeth by the bristles. The two portions may be movable independently of each other, but this movement is passive in that it is only caused by pressure applied on the regions during brushing
U.S. Publication No. 2004/0177462 in the name of Brown, Jr. et al, which again is assigned to The Gillette Company, discloses a manual toothbrush that has a head which is split into two portions. The split in the head permits the two portions to flex or move independently of each other but, once again that movement is passive in that it is only caused by pressure applied to the bristles by the teeth during brushing. An opening is defined between the two movable portions and the opening permits water and debris removed from the teeth to flow through this opening.
U.S. Pat. No. 5,987,681 issued to Hahn et al discloses an electric toothbrush that includes a mechanism for vibrating the head and therefore the tooth cleaning elements or bristles mounted thereon. The toothbrush includes a handle which houses a rotary motor. An unbalanced weight is provided on one or both sides of a shank close to the head of the brush. A drive shaft extends outwardly from the motor and drives the shank. When the motor is activated then the head of the toothbrush is vibrated.
There is therefore a need in the art for a toothbrush that includes a mechanism for actively moving the two portions of a split head type toothbrush to improve the cleaning power of the brush.
SUMMARY OF THE INVENTION
The device of the present invention comprises a toothbrush having head with at least two movable members. The members flex inwardly and outwardly away from each other in a direction that is substantially at right angles to the longitudinal axis of the brush handle. Force is transferred from one movable member to another to aid in this relative movement. Bristles extending from both movable members are brought into contact with the surface of teeth so that the tips are disposed at right angles thereto. In a first embodiment, two movable members are connected by an oscillating rod that flexes the members away from each other. In a second embodiment, a center section on the head nests within a perimeter section and a rotatable cam extends between the sections and flexes them inwardly and outwardly away from each other.
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 side view of the electric toothbrush in accordance with the present invention;
FIG. 2 is an enlarged cross-sectional side view of the toothbrush FIG. 3 is an enlarged cross-sectional side view of the toothbrush shown from the end of the first camshaft section to the tip of the head;
FIG. 4 is a top view of the toothbrush head taken through line 4-4 of FIG. 3;
FIG. 5 is an exploded left perspective view of the first and second head sections shown with the bristles removed therefrom for clarity;
FIG. 5
a is an exploded right perspective view of first and second head sections with the bristles removed;
FIG. 5
b is a rear view of the first and second head sections attached to each other and showing the camshaft extending through the neck portion and into the body portion of the head;
FIG. 6 is a front view of the motor and the camshaft removed from the toothbrush;
FIG. 7 is a cross-sectional side view of a portion of the toothbrush with the bristles removed and showing the camshaft in position to flex the first and second sections away from each other;
FIG. 8 is a side view of the portion of the toothbrush shown in FIG. 7 and showing the second head section being moved toward the right by the camshaft and the first head section being moved toward the left;
FIG. 9 is a bottom view of the first and second head sections in a flexed position and taken through line 9-9 of FIG. 8;
FIG. 10 is a cross-sectional side view of a portion of the toothbrush head where the camshaft is causing the second head section being moved toward the left and the first head section being moved to the right;
FIG. 11 is a side view of the portion of the toothbrush shown in FIG. 10 and showing the first head section being moved toward the right by the camshaft and the second head section being moved toward the left;
FIG. 12 is a bottom view of the first and second head sections in a flexed position and taken through line 12-12 of FIG. 11;
FIG. 13 is cross-sectional side view of a portion of the toothbrush and showing the connection between the camshaft and the drive shaft upon pressure being applied to the bristles and therefore the head in response to pressure being applied to the bristles during brushing;
FIG. 14 is a side view of the portion of the toothbrush shown in FIG. 13;
FIG. 15 is an exploded side view of a second embodiment of the toothbrush showing that the head thereof is detachably connectable to the handle;
FIG. 16 is an exploded cross-sectional side view of the toothbrush of FIG. 15 shown from the motor to the tip of the head;
FIG. 17 is a perspective view of a third embodiment of a toothbrush in accordance with the present invention;
FIG. 18 is a partially exploded perspective view of the toothbrush of FIG. 17;
FIG. 19 is a perspective view of the toothbrush of FIG. 17 with the right-hand side of the head removed to show the shaft engaged with the left-hand side of the head;
FIG. 20 is a front elevational view of the toothbrush;
FIG. 21 is a cross-sectional top view of the toothbrush handle taken through line A-A of FIG. 20 and showing the drive shaft extending from the handle in a neutral position;
FIG. 21
a is a cross-sectional top view of the toothbrush handle taken through line A-A of FIG. 20 and showing the drive shaft in a first position;
FIG. 21
b is a cross-sectional top view of the toothbrush handle taken through line A-A of FIG. 20 and showing the drive shaft in a second position;
FIG. 22 is a cross-sectional bottom view of the head of the shaft taken through line B-B of FIG. 20;
FIG. 23 is a cross-sectional bottom view of the head taken through line C-C of FIG. 20 and showing the leg portion of the drive shaft and the two head sections in a neutral position;
FIG. 23
a is a cross-sectional bottom view of the head taken through line C-C of FIG. 20 and showing the leg portion of the drive shaft and the two head sections in a first position;
FIG. 23
b is a cross-sectional bottom view of the head taken through line C-C of FIG. 20 and showing the leg portion of the drive shaft and the two head sections in a second position;
FIG. 24 is a perspective front view of a fourth embodiment of a powered toothbrush in accordance with the present invention;
FIG. 25 is an enlarged perspective view of the highlighted portion of FIG. 24;
FIG. 26 is a perspective rear view of the toothbrush of FIG. 24;
FIG. 27 is a front view of the toothbrush of FIG. 24;
FIG. 28 is a cross-sectional side view taken through line 28-28 of FIG. 27;
FIG. 29 is an enlargement of the highlighted area of FIG. 28 showing the toothbrush head in the neutral position;
FIG. 30 is a cross-sectional side view of the head of the toothbrush showing the center section in a first flexed position; and
FIG. 31 is a cross-sectional side view of the head of the toothbrush showing the center section in a second flexed position.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1-14 there is shown a first embodiment of an electric toothbrush in accordance with the present invention and generally indicated at 10. Toothbrush 10 includes a handle 12 and a head 14 and has a longitudinal axis “X” (FIG. 1). In the first embodiment, handle 12 and head 14 are integrally formed with each other. Handle 12 is ergonomically designed so that it is easily gripped in that a first surface 16 thereof is contoured and textured with ribs 18. A second surface 20 of handle 12 houses the control button 22 for activating brush 10 and control button 23 for deactivating brush 10. The bottom end 24 of handle 12 may be unscrewed or otherwise detached to allow access to a battery compartment within handle 12.
Referring to FIG. 2, a motor 26 is housed within an interior cavity 28 of handle 12. Motor 26 is driven by one or more batteries, but preferably by a single AAA battery. A drive shaft 30 extends outwardly from motor 26 and into a lower portion of the neck 50 of brush 10. One end of a camshaft abuts an end of drive shaft 30. The camshaft comprises a shorter first camshaft section 32 and a longer second camshaft section 34 which are in end to end contact with each other. First camshaft section 32 abuts the end of drive shaft 30. A second end of first camshaft section 32 abuts second camshaft section 34. A coiled flexible spring 36 tightly surrounds a portion of drive shaft 30, the entire length of first camshaft section 32 and a portion of second camshaft section 34. Spring 36 maintains a flexible contact between drive shaft 30, first camshaft section 32 and second camshaft section 34 and ensures that any motion of drive shaft 30 is imparted to second camshaft section 34. Spring 36 also ensures that if head 14 is bent backwardly during brushing, first camshaft section 32 does not become misaligned with motor 26. This flexible operational contact is illustrated in FIGS. 13 and 14.
Second camshaft section 34 is a thin rod manufactured from stainless steel. Second camshaft section 34 passes through a soft rubber seal 38 and into head 14, terminating at a point underneath the region of the head where bristles 53 are mounted. Seal 38 is provided to prevent water and debris removed from the teeth during brush from entering cavity 40. Second camshaft section 34 terminates in a first and a second cam lobe 42, 44 (FIGS. 3 and 6). First and second cam lobes 42, 44 are offset relative to each other and to the main shaft 34a of second camshaft section 34.
Referring to FIGS. 5-5b and in accordance with a specific feature of the present invention, head 14 of toothbrush 10 is manufactured from two separate molded head sections 46, 48. Each head section 46, 48 includes a neck portion 54 and a body portion 56. When head sections 46, 48 are joined together, the two neck portions 54a, 54b (FIG. 5a) form the elongated, thinner neck 50 of brush 10, and the two body portions 56a, 56b form the wider body 52. A plurality of bristles or bristle tufts 53 extend outwardly from one of the surfaces of body 52. Preferably, bristles or bristle tufts 53 are fixedly mounted to body 52 and only flex relative thereto as opposed to the bristles being pivotally or rotatably mounted within body 52.
Each body portion 56a, 56b of head sections 46, 48 is provided with an arcuately contoured inner wall 58a, 58b. Neck portions 54a, 54b are each provided with an angular or planar inner wall 60a, 60b. The contours of the inner wall 58a are complementary to the contours of inner wall 58b and are designed to substantially mesh with each other. Inner walls 60a, 60b are also complementary and designed to mate with each other when brush 10 is assembled during manufacture.
FIG. 5 shows head section 48 in greater detail. Inner wall 58b of head section 48 is shaped to form a plurality of arcuate protrusions 62 and recesses 64. A first protrusion 62a defines an aperture 66 therein that is aligned with longitudinal axis “X” of brush 10. Aperture 66 is four-sided in cross-sectional shape, being substantially rectangular or square in cross-sectional shape. A second protrusion 62b of inner wall 58b defines an axially aligned slot 68 therethrough. Slot 68 is substantially U-shaped in cross-section. The shape of aperture 66 and slot 68 substantially resists the tendency of head portions 46, 48 to split apart in response to rotation of camshaft lobes 42, 44. Neck portion 54b of head section 48 is substantially C-shaped in cross-section and tapers in size from end 70 toward body portion 56b. An elongated narrow channel 72 is defined in that part of neck portion 54b proximate body portion 56b. Channel 72 is longitudinally aligned and substantially continuous with slot 68. Head section 48 includes a plurality of holes 69 in an upper surface thereof. These holes are provided for mounting bristles 53 therein.
FIG. 5
a shows inner wall 58a of head section 46 in greater detail. Inner wall 58a is similarly configured to inner wall 58b in that it includes a plurality of arcuate protrusions 62c, 62d and recesses 65. Protrusions 62c, 62d on inner wall 58a are designed to mesh with the protrusions 62a, 62b on inner wall 58b. So, for example, protrusion 62c on inner wall 58a meshes with protrusions 62a and 62b on inner wall 58b. Furthermore, protrusion 62c defines an aperture 67 therein that is alignable with aperture 66 in protrusion 62a and with slot 68 in protrusion 62b. Aperture 67 is four sided in cross-sectional shape. Furthermore second protrusion 62b has planar interior walls that define slot 68. When apertures 66, 67, slot 68 and channel 72 are aligned, an elongated bore 76 is formed which extends through head 14 and terminates only a short distance away from tip 74 of brush 10. Second camshaft section 34 is received through this bore 76. When second camshaft section 34 is engaged in bore 76, and specifically when the first and second lobes 42, 44 are retained in the four-sided apertures 66, 67 respectively, first and second head sections 46, 48 are substantially prevented from separating laterally from each other.
FIG. 5
b shows that when head sections 46, 48 are secured together by gluing or heat welding, the inner walls 60a, 60b of the two neck portions 54a, 54b are attached together from end 70 to a point “A”. Point “A” is disposed a spaced distance away from a point “B” where body 52 of head 14 originates. The remaining length of inner walls 60a, 60b and all of inner walls 58a, 58b from point “B” to tip 74 are not secured together in any way. A narrow channel 72 is formed between inner walls 58a, 58b and extends for a distance between inner walls 60a, 60b. Channel 72 originates at point “A” and terminates at tip 74 of head 14. Channel 72 permits water and debris removed from the teeth to be flushed away from bristles 53. The presence of channel 72 also enables the body portions and the unattached parts of the neck of head sections 46, 48 to flex relatively easily upwardly and downwardly out of alignment with each other as shown in FIG. 8.
This possible relative movement between head sections 46, 48 is not, however only a passive movement caused by the bristles 53 engaging the teeth during brushing. The transverse movement of head sections 46, 48 relative to each other and to the longitudinal axis “X” of brush 10 is also a movement powered by the camming action of second camshaft section 34. Second camshaft section 34 extends through bore 76 and engages both of head sections 46, 48. The shaft 34a of second camshaft section 34 extends through channel 72 of head sections 46, 48. The first cam lobe 42 of second camshaft section 34 extends through the aperture or groove 67 (FIG. 3) in protrusion 62c of head section 46. The second cam lobe 44 is seated in aperture 66 in first protrusion 62a of head section 48. FIG. 5b shows that parts of second camshaft section 34 are visible through channel 72 and holes 78 in back surface 14b of head 14. Rotational movement generated by motor 26 causes second camshaft section 34 to rotate in bore 76. Because second camshaft section 34 extends into body portion 52 of head 14 and terminates in a region beneath bristles 53, the rotational motion of second camshaft section 34 is transmitted directly to first and second head sections 46, 48 through the action of cam lobes 42, 44. The motion of head sections 46, 48 relative to each other in response to the action of cam lobes 42, 44 is shown in FIGS. 7-12.
FIGS. 7-9 show second camshaft section 34 in a first position with cam lobe 44 forcing head section 48 to move out of alignment with head section 46 in the direction of arrow “Y”. The relative displacement is shown in FIG. 9. FIGS. 10-12 show second camshaft section 34 rotated through 180°. In this position, cam lobe 44 is oriented in such a manner that head section 48 has moved back into a rest position and is substantially aligned with head section 46 once again. As second camshaft section 34 continues to rotate through another 180°, cam lobe 44 moves once again into the position shown in FIG. 7 and head section 48 moves again in the direction of arrow “Y” and into the position shown in FIG. 8. Thus, head section 48 is caused to move alternatively into and out of alignment with head section 46 and longitudinal axis “X” of brush 10. These movements are very small and very rapid.
The entire head 14 of brush 10 is also able to flex somewhat in response to pressure applied on head 14 during brushing. As shown in FIGS. 13 & 14 this flexing motion may cause second camshaft section 34 to become misaligned with first cam section 32 and drive shaft 30. However, the flexible spring 36 maintains contact between second camshaft section 34, first cam section 32 and drive shaft 30, so that even in this flexed head position, head sections 46, 48 continue to be able to move independently of each other in response to rotation of second camshaft section 34.
Because bristles 53 are mounted onto head sections 46, 48, the movement of head sections 46, 48 in response to rotation of the second camshaft section 34 causes a corresponding motion in bristles 53. These movements in the transverse directions are very rapid and small in amplitude. This reduces the drag on bristles 53 as they engage the teeth and also reduces the amount of power the brush 10 uses. Consequently, toothbrush head continues to move when bristles contact the teeth, unlike the toothbrushes known in the prior art. Toothbrush 10 therefore has an active head 14 that is more efficient at removing particulate matter from the teeth.
FIGS. 15 and 16 show a second embodiment of a toothbrush in accordance with the present invention and generally indicated at 110. In this second embodiment, the head 114 of brush 110 is removable from the handle 112. The detachable head 114 may be removed from handle 112 if bristles 153 become damaged through use, for example. A replacement head (not shown) may then be snap-fitted or otherwise secured to handle 112. As with the previous embodiment, handle 112 is contoured and includes ribs for gripping and control buttons 122, 123 on front surface 120. The other various components and operation of toothbrush 110 are substantially identical to those of toothbrush 10 except that flexible spring 136 surrounds the first camshaft section 132 and a portion of longer camshaft section 134. First camshaft section 132 is secured to in a female connector 190 that projects slightly from the bottom end 114b of head 114. Drive shaft 130 is secured to a male connector 192 that is complementary to female connector 190. Male and female mating connectors 190, 192 are designed to mechanically and electrically connect drive shaft 130 to camshaft 134. It will be understood that female connector 190 may be secured to drive shaft 130 and male connector 192 may be secured to shorter camshaft section 132 without departing from the spirit of the present invention. Additionally, the male upper end 112a of handle 112 is complementary shaped to interlock with the female bottom end 114b of head 114. Head 114 is snap-fitted onto handle 112 and the two parts may be secured together by any other suitable means that will prevent the head 114 from separating accidentally from the handle 112 during brushing. It will be understood that the interlocking male and female ends of handle 112 and head 114 may alternatively be provided on the opposite components without departing from the spirit of the present invention.
It will be understood that while the camshaft is shown as comprising first camshaft section 32 and second camshaft section 34, a single continuous camshaft may be used in toothbrush 10.
Referring to FIGS. 17-23, there is shown a third embodiment of a powered toothbrush in accordance with the present invention and generally indicated at 210. Toothbrush 210 includes a handle 212 and a head 214. Handle 212 is not shown in any detail in these figures but could be of any suitable shape and include components such as on/off buttons, gripping ribs etc. A drive shaft 280 extends outwardly from handle 212 and is operationally connected to a motor (not shown) housed within handle 212. A connector 282 extends outwardly from drive shaft 280.
Head 214 is comprised of two complementary head sections 246, 248 that are laterally disposed relative to each other. Head sections 246, 248 are substantially mirror images of the other. Each head section includes an elongated neck portion 254 and a body portion 256 that extends outwardly away therefrom. A plurality of bristles 253 or bristle tufts are provided on body portion 256. As with the first and second embodiments of the toothbrush, the neck portions 254 of the two head sections 246, 248 are substantially connected together while the body portions 256 thereof are substantially independent of each other and are separated from each other by a gap 301 (FIG. 23). Body portions 256 of the first and second head sections 246, 248 are movable relative to each other in flexure.
In accordance with a specific feature of the present invention a substantially T-shaped coupler rod 295 is provided to aid the movement of head sections 246, 248. Coupler rod 295 is a substantially T-shaped member comprising a coupler shaft 297 that is substantially longitudinally aligned with the longitudinal axis “X” of handle 212. A leg 299 is provided at one end of shaft 297 and is disposed substantially at right angles to shaft 297. A connector 296 is provided at an end of coupler shaft 297 remote from let 297. Connector 296 includes a longitudinally aligned slot 298 that extends for a distance into connector 296. Slot 298 interlockingly engages a connector 282 on a drive shaft 280 that extends outwardly from handle 212. Connector 296 and slot 298 are complementary in size and shape so that connectors 296, 282 are tightly secured together. It will be understood that connector 296 may be different configured to be connectable to any shape or size of connector 282 extending from a drive shaft 280. Coupler rod 295 preferably is manufactured from a plastic such as nylon.
Leg 299 includes a bulbous member at either end, namely bulbous members 300, 302. Bulbous member 300 is configured to engage head section 246 and bulbous member 302 is configured to engage head section 248. Bulbous members 300, 302 effectively act as camming surfaces on coupler rod 295 during operation of toothbrush 210.
In accordance with another feature of the present invention, each head section 246, 248 defines a portion of a longitudinally aligned channel 272 configured to receive the T-shaped coupler rod 295 therein. In each head section 246, 248, the portion of channel 272 is generally C-shaped in cross-section and extends from bottom end 214a of head 214 to a position spaced inwardly from tip 270. As shown in FIG. 18, channel 272 extends for a distance beneath the surface of body portion 256 into which bristles 253 are secured. Each portion of channel 272 defines a first chamber 274 that is complementary sized and shaped to receive a part of connector 296 therein. When first and second head sections 246, 248 are joined together, connector 296 is retained in the combined first chambers 274 of the two portions of channel 272. The portion of channel 272 in each head section 246, 248 further defines a second chamber 276 which is spaced from first chamber 274. Second chamber 276 is complementary shaped and sized to receive part of leg 299 and one of bulbous members 300, 302 therein. Coupler shaft 297 is retained in the region of channel 272 that extends between first and second chambers 274, 276. FIG. 19 shows toothbrush 210 with head section 248 removed so that the coupler rod 295 may be seen engaged in channel 272, first chamber 274 and second chamber (not numbered) of head section 246.
Toothbrush 210 operates in the following manner. Initially, when toothbrush 210 is not powered, drive shaft 280 is in a neutral position (FIG. 21) and, consequently, coupler rod 295 is also in a neutral position (FIG. 23). The user activates brush 210 by depressing control button 222. This activates a motor (not shown) which oscillates drive shaft 280 back and forth between a first and a second position as shown in FIGS. 21a and 21b. The oscillatory movement of drive shaft 280 is transferred to coupler rod 295 by interlocked connectors 282, 296. Coupler rod 295 is therefore caused to oscillate back and forth between a first and second position as shown in FIGS. 23a and 23b. This motion causes the coupler rod 295 to move through an arcuate path “Z” that is oriented substantially at right angles to the longitudinal axis of the toothbrush as shown in FIG. 23. The range of motion of coupler rod 295 is such that bulbous members 300, 302 on leg 299 are moved through an angle of between ten degrees and sixty-five degrees between the first and second positions. Preferably, the range of motion is about fifty degrees between the first and second positions, i.e., about twenty-five degrees above and below the neutral position. The coupler rod 295 is oscillated rapidly between the first and second positions.
The movement of leg 299 from a neutral position to a first position (FIG. 23a) causes bulbous member 300 to push the body portion 256 of head section 246 downwardly and causes bulbous member 302 to push the body portion 256 of head section 248 upwardly. As coupler rod 295 continues to oscillate, leg 299 moves through the neutral position (FIG. 23) and on to the second position (FIG. 23b). The movement of leg 299 from the neutral position to the second position causes bulbous member 302 to push head section 248 downwardly and bulbous member 300 to push head section 246 upwardly.
Leg 299 effectively acts as a lever, transferring energy back and forth between the two head sections 246, 248. When head section 246 moves downwardly relative to head section 248, the engagement of leg 299 with head section 246 levers head section 248 upwardly. This levering action causes the plastic material of body portion 256 of head section 248 to be flexed relative to neck portion 254 thereof, thereby storing potential energy in flexed head section 248. Similarly, the material of body portion 256 of head section 246 is also flexed relative to neck portion 254 thereof. Thus, potential energy is also stored in flexed head section 246. The potential energy is released from both head sections 246, 248 as the coupler rod 295 oscillates toward the neutral position. This release and transfer of energy drives leg 299 to rotate in the opposite direction resulting in both head sections 246, 248 being flexed in the opposite direction. The potential energy released by the flexed body portions 256 thus aids in moving head sections 246, 248 relative to each. The system therefore requires less energy to run than would be the case if there was no flexure of the two head sections 246, 248. Toothbrush 210 therefore comprises two head sections 246, 248 that are movable relative to each other and the force from head section 246 causes movement in head section 248, and force from head section 248 causes movement in head section 246. First and second head sections 246, 248 are movable relative to each other free of a frame.
It should be noted that if the relative movement between head section 246 and 248 is dampened or stopped by the user biting down on the brush or the bristles, for example, then coupler shaft 297 would torsionally twist as the head sections 246, 248 flex to allow the motor to continue running until the force on the head 214 is released.
While toothbrush 210 is illustrated as a unit having a handle 212 and head 214 that are permanently connected together, it will be understood that toothbrush 210 may instead comprise a separate handle portion and head portion that are snap-fitted together in the same way as the toothbrush 110 disclosed in FIGS. 15 and 16.
Referring to FIGS. 24-30, there is shown a fourth embodiment of a powered toothbrush in accordance with the present invention and generally indicated at 310. Toothbrush 310 includes a handle 312 and a head 314. As with previous embodiments, handle 312 is ergonomically contoured for easy gripping and includes a plurality of ribs 318 and control buttons 322, 323. Head 314 comprises a neck 350 and a body 349. Body 349 includes two movable sections, namely a perimeter section 346 and a center section 348. Center section 348 nests inside perimeter section 346 (FIG. 26). Center section 348 is free of connection to perimeter section 346 along its sides, 348a, 348b, 348c. Center section 348 is connected to perimeter section 346 along a single face 348d which is situated proximate an edge area of body 349 proximate neck 350. Interior end 348a is situated proximate an interior region of body 349.
A plurality of bristles 353 extend outwardly away from a front surface of each of perimeter and center sections 346, 348, with the bristles on center section 346 being identified as 353a and the bristles on perimeter section being identified as 353b. It will be understood that while perimeter section 346 is shown to be generally U-shaped and disposed around a substantially smaller and generally rectangular center section 348, perimeter and center sections 346, 348 may be of any desired shape. Center section 348 forms a central, inwardly extending tongue that is separated from perimeter section 346 by a gap 351 (FIG. 29) Center section 348 is able to flex inwardly and outwardly relative to front face 346a of perimeter section 346 as will be hereinafter described. Perimeter and center sections 346, 348 move relative to each other without a frame supporting this movement.
As shown in FIGS. 28-31, a drive shaft 330 extends outwardly from a motor 341 housed in handle 312. Drive shaft 330 extends into an interior cavity 340 of neck 350. A camshaft 332 is operationally connected to drive shaft 330 and extends forwardly therefrom and into engagement with perimeter and center sections 346, 348. A flexible spring 336 is secured around a portion of each of the drive and cam shafts 330, 332. Cam shaft 332 includes a first cam lobe 342 and a second cam lobe 344. First cam lobe 342 engages perimeter section 346, most specifically region 346b (FIG. 29) that is adjacent inner region 348a of center section 348. Second cam lobe 344 engages center section 348. First and second cam lobes 342, 344 are longitudinally offset relative to each other as previously described with respect to the camshaft provided in toothbrush 10. The offset 343 between first and second cam lobes 342, 344 occurs in the vicinity of the gap 351 between inner region 348a of center section 348 and region 346a of perimeter section 346. When toothbrush 310 is activated via control button 322, cam shaft 332 is rotated through 360°. As cam shaft 332 rotates through 180 ° from a first position shown in FIG. 29 to a second position shown in FIG. 30, second cam lobe 344 pushes inner region 348a of center section 348 outwardly away from perimeter section 346 in the direction indicated by arrow “D”. This causes center section 348 to flex, with the region of least flexure being proximate face 348d and the region of greatest flexure being proximate inner region 348a. When this occurs, center section 348 flexes about face 348d until it is disposed at an angle “S” relative to front face 346a of perimeter section 346 (FIG. 30). At the same time, first cam lobe 342 pushes the region 346b of perimeter section 346 outwardly away from inner region 348a in the opposite direction to “D”. Thus, region 346b of perimeter section 346 is flexed outwardly away from center section 348, but to a much lesser extent because perimeter section 346 is larger than center section 348 and is more rigidly secured to neck 350. The flexure of both center section 348 and perimeter section 346 stores potential energy in head 314.
As cam shaft 332 continues to rotate through another 180° and back into the first position (FIG. 29), second cam lobe 344 ceases to push inner region 348a of center section 348 in the direction “D”. The potential energy stored in the flexed center section 348 is released and transmitted via cam shaft 332 to first cam lobe 342 and therefore to perimeter section 346. The transferred force causes center section 348 and perimeter section 346 to be flexed slightly away from each other in the opposite direction. Continued rotation of cam shaft 332 causes the outward pressure on the oppositely flexed center section 348 to be relieved and the potential energy stored in the flexed center section 348 to be transferred back through the cam shaft 322 to perimeter section 346 The transferred force again aids in flexing the center section 348 away from the perimeter section 346 and back in the direction of arrow “D”. The continued rotation of cam shaft 332 at high speed causes a reciprocating in-and-out motion of center section 348 relative to front face 346a of perimeter section 346. The continued cycle of storing and releasing energy from the flexure of perimeter and center sections 346, 348 reduces the energy required to rotate cam shaft 332 to move sections 346, 348.
When center section 348 is in the first neutral position (FIG. 29), the bristles 353a on center section 348 are substantially aligned with bristles 353b on perimeter section 346. This configuration will exist when toothbrush 310 is in a deactivated condition. When toothbrush is activated, center section 348 is flexed into the second position (FIG. 30), the bristles 353a on center section 348 are disposed outwardly relative to bristles 353b on perimeter section 346. Furthermore, bristles 353a are disposed at an angle relative to bristles 353b because they extend outwardly from flexed center section 348. The bristles proximate inner region 348a are disposed farther outwardly away from front face 346a of perimeter section 346 than all of the other bristles on head 314. Continued rotation of cam shaft 332 will cause center section 348 to move into a third position (FIG. 31) where center section is flexed in the opposite direction. When in this position, bristles 353a may be slightly recessed relative to bristles 353b. Consequently, as cam shaft 332 is rotated, bristles 353a move more forcefully into and out of contact with the teeth. This rapid impacting motion in the central region of the brush head, combined with the angle of attack of bristles 353a permits improved removal of particulate material from the teeth.
Thus, an improved method of cleaning teeth using the toothbrushes of the present invention comprises activating the powered toothbrush to cause relative movement between two members on the head of the toothbrush. This relative movement is in a direction that is substantially at right angles to the longitudinal axis of the handle of the brush and substantially aligned with the longitudinal axes of the bristles prior to engagement with the teeth. The inward and outward movement of the bristles, toward and away from the teeth, causes an impact motion on the surface of the teeth. Furthermore, the inward and outward motion causes the bristles themselves to flex as they are pushed inwardly toward the teeth by the movable members on the toothbrush head.
When the inward movement is released by the movable member moving outwardly away from the surface of the teeth, the energy stored in the flexed bristles causes particulate matter to be forcefully swept off the surface of the teeth. Furthermore, the inward and outward movement of the bristles caused by the movable members on the head, also aids the bristles in reaching lower contoured surfaces of the teeth.
It will be understood that while the toothbrush of the present invention has been disclosed as having two movable members, it will be understood that more than two movable members can be provided to form the head of the toothbrush.
In the various embodiments of a powered toothbrush disclosed herein, substantially all of the energy required to move the movable parts relative to each other is released within the head of the brush, thereby substantially reducing vibration in the handle to a negligible amount. Substantially the entire head of the brush is pulsed with a first part of the head moving upwardly and a second part moving downwardly, and then the second part of the head moving upwardly with the first part moving downwardly. The system for moving the first and second parts of the head is designed so that energy is stored on each stroke and is released in the next stroke. The system utilizes the characteristics of the plastic material of the head of the brush to flex or bend thereby storing the energy for the next stroke. This results in the drive system being between 250% and 300% more energy efficient than if the system was simply set up to accelerate the brush head in one direction, then decelerate the head to a neutral position and then accelerate the head in the opposite direction. Consequently, the toothbrush can be powered with a single standard AAA battery or can be rechargeable. This reduced power requirement also enables the toothbrush to be made in a much more lightweight format than previously known powered toothbrushes.
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.
Patent Application
20090019650
