CN112423621A

CN112423621A - Tooth treatment appliance

Info

Publication number: CN112423621A
Application number: CN201980047232.3A
Authority: CN
Inventors: T.米勒; R.特威迪
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2018-07-18
Filing date: 2019-05-17
Publication date: 2021-02-26
Also published as: GB2575659A; GB201811744D0; WO2020016547A1; GB2575659B

Abstract

A dental treatment appliance includes a fluid reservoir for storing a working fluid, and a fluid delivery system for receiving the working fluid from the reservoir and delivering the working fluid to an oral cavity of a user. The fluid reservoir includes a fluid port and a core for delivering a working fluid to the fluid port.

Description

Tooth treatment appliance

Technical Field

The present invention relates to a treatment instrument. The treatment appliance is preferably a hand-held treatment appliance, and is preferably a surface treatment appliance. In a preferred embodiment of the invention, the appliance is a dental treatment appliance. In a preferred embodiment, the appliance is a power toothbrush having a fluid delivery system for delivering fluid to the mouth of a user. This fluid is a toothpaste, or a fluid for improved interproximal cleaning. Alternatively, the appliance may not include any bristles or other elements for brushing the teeth, and may be in the form of a dedicated interdental treatment appliance.

Background

Electric toothbrushes typically include an implement connected to a handle. The tool includes a shaft and a brush head carrying bristles for brushing teeth. The brush head includes a fixed section connected to a rod and at least one movable section that is movable relative to the fixed section, such as one of a reciprocating, oscillating, vibrating, pivoting, or rotating motion, to impart a brushing motion to bristles mounted thereon. The rod houses a drive shaft that is coupled to a transmission unit within the handle. The transmission unit is in turn connected to an electric motor driven by a battery housed within the handle. The drive shaft and transmission unit converts the rotational or vibratory motion of the motor into the desired movement of the movable section of the brushhead relative to the fixed section of the brushhead.

It is known to incorporate fluid delivery systems into electric toothbrushes for generating jets of working fluid for interdental cleaning. For example, WO2016/185166 describes a toothbrush having a handle and a brush head comprising a nozzle from which a working fluid is delivered to the mouth of a user. The nozzle is movable relative to the handle as the appliance is moved along the teeth of the user. The toothbrush can be operated in one of two different modes. In a first mode, the user depresses the button to actuate the delivery of working fluid from the nozzle. In a second mode, the control circuit automatically actuates delivery of working fluid to the nozzle in accordance with signals received from the sensor to detect movement of the nozzle relative to the handle, for example, when the nozzle moves into or out of the interproximal spaces between the user's teeth.

The toothbrush includes a fluid reservoir surrounding a shaft extending between the handle and the head. The fluid reservoir includes a fluid port that is connectable to a fluid delivery system and through which working fluid is drawn into the fluid delivery system. The handle includes a seal around the fluid port to prevent leakage of the working fluid from the fluid reservoir. The fluid reservoir may be rotated about the shaft to expose the fluid port to allow the fluid reservoir to be replenished. The fluid port is toward a bottom of the outer wall of the fluid reservoir. When the volume of working fluid is relatively low, there is a risk that the level of working fluid remaining in the fluid chamber is below the fluid port, depending on the orientation in which the appliance is held, and therefore in this orientation the working fluid may not be drawn into the fluid delivery system.

Disclosure of Invention

In a first aspect, the present invention provides a dental treatment appliance comprising:

a fluid reservoir for storing a working fluid; and

a fluid delivery system for receiving the working fluid from the reservoir and for delivering the working fluid to the oral cavity of a user,

wherein the fluid reservoir comprises a fluid port and a core for delivering a working fluid to the fluid port.

The provision of a wick may increase the likelihood that the working fluid will be drawn into the fluid delivery system regardless of the current orientation of the appliance.

The core is preferably formed from an absorbent sponge or foam material. The core is preferably formed of a water absorbent material, and is preferably formed of a water absorbent sponge material. Preferably, the core is formed of polyurethane. Commercially available materials from which the core may be formed include Capu-Cell^TMFoam, available from Foam Sciences.

The core comprises a material that is soluble in a working fluid stored in the fluid reservoir. The dissolvable material may be provided in the form of a coating or layer of material applied to the surface of the core. The dissolvable material includes a water soluble phosphate. The phosphate material may be in the form of a phosphate glass, such as sodium calcium phosphate or sodium calcium silicophosphate, which will slowly dissolve in water stored in the fluid reservoir to release minerals such as calcium sulfate, sodium phosphate, and silicon dioxide. Calcium ions in the release material may be beneficial in re-calcifying cavities or lesions in the enamel formed in the user's teeth, while silica is widely used in toothpaste for stain removal.

The dissolvable material may comprise a dissolvable matrix impregnated with solid particles that disperse within the stored working fluid when the matrix dissolves into the working fluid. The solid particles may include, for example, mica or glycine particles that are delivered to the user's teeth in a jet of working fluid, e.g., to help remove material located in the user's interdental spaces, or to disrupt the plaque layer formed on the user's teeth. The solid particles may comprise sodium calcium phosphate glass particles, which may fill channels present in sensitive teeth, or titanium dioxide particles.

The dissolvable matrix may comprise inorganic or organic materials such as acrylates or vinyl polymers. Such materials may also be provided without solid particles, and may be surface active materials, which may aid in the tooth cleaning process. The organic polymeric material may be functionalized, for example with lauryl sulfate groups, to improve the cleaning process, or to deliver fluoride or chelating agents such as EDTA (ethylene diamine tetraacetic acid). The dissolvable material may also include an organic polymer that inhibits the accumulation of scale or microorganisms in the fluid reservoir.

The dissolvable material may also include other materials, such as fluoride for improved tooth cleaning, or antimicrobial materials. For example, the dissolvable material may include silver particles having antimicrobial properties.

The core is preferably located within the fluid reservoir and preferably extends along the length of the fluid reservoir, the length of the fluid reservoir being measured in a direction extending parallel to the longitudinal axis of the appliance.

The core may be shaped so as to occupy substantially the entire fluid reservoir, or so as to occupy only a portion of the fluid reservoir. In a preferred embodiment, the fluid reservoir includes a perforated wall that divides the fluid reservoir into an upstream chamber and a downstream chamber. The downstream chamber receives working fluid from the upstream chamber and delivers the working fluid to the fluid port. The core is located in the downstream cavity. Preferably, the core substantially fills the downstream cavity. On the other hand, the upstream chamber is preferably substantially free of wicking or sponge material.

In order to maximise the capacity of the fluid reservoir and provide a relatively even weight distribution about the longitudinal axis of the appliance, the fluid reservoir preferably extends about at least a portion of the handle of the appliance. In a preferred embodiment, the fluid reservoir surrounds the handle. The fluid reservoir is preferably annular in shape. The upstream chamber preferably extends about or around the downstream chamber. Each of the upstream and downstream chambers is preferably annular in shape.

Preferably, the fluid reservoir comprises a base extending between an inner wall and an outer wall of the fluid reservoir, wherein the fluid port is formed in the base. The perforated wall is preferably annular in shape and preferably extends around the inner wall, wherein the outer wall extends around the perforated wall. The fluid delivery system preferably includes a flexible conduit for delivering the working fluid away from the fluid reservoir. The flexible conduit includes an inlet connectable to the fluid port to place the fluid delivery system in fluid communication with the fluid reservoir. The fluid reservoir may be filled through the fluid port by disconnecting the flexible conduit from the fluid reservoir, but in a preferred embodiment the fluid reservoir comprises a fluid inlet port, wherein the upstream chamber is arranged to receive working fluid directly from the fluid inlet port.

Preferably, the fluid reservoir is movable relative to, and more preferably along, the handle to expose the fluid inlet port for replenishing the fluid reservoir. By moving the fluid reservoir along the length of the handle, rather than rotating the fluid reservoir about the rod, wear of any seals used to engage the fluid reservoir may be reduced.

The fluid reservoir is preferably movable between a first position in which the fluid inlet port is closed and a second position in which the fluid inlet port is exposed to replenish the fluid reservoir. The fluid reservoir is freely movable to one of a plurality of different positions intermediate the first position and the second position. Alternatively, the fluid reservoir may be urged toward the first position or the second position depending on the position of the fluid reservoir relative to the handle. For example, the appliance may comprise a spring mechanism (e.g. an over-center mechanism) for urging the fluid reservoir towards the first or second position, or a magnet arrangement for attracting the fluid reservoir towards the first or second position, depending on the current position of the fluid reservoir relative to the handle. The fluid reservoir is preferably slidable along the handle.

The dental delivery system preferably includes a nozzle for delivering the working fluid to the mouth of the user. The fluid delivery system preferably further comprises a pump and a controller for actuating the pump to draw working fluid from the fluid reservoir and to send the working fluid towards the nozzle. As the nozzle is moved between the user's adjacent teeth, the user may press a button of a user interface disposed on the handle to actuate the pump to cause the working fluid to be emitted from the nozzle. Alternatively, the appliance may be configured to automatically actuate the delivery of working fluid to the mouth of the user at a fixed frequency (e.g., between 0.5 and 5 Hz). The controller is preferably arranged to actuate the pump to emit a jet of the working fluid towards the nozzle. The volume of each jet of working fluid produced by the fluid delivery system is preferably less than 1ml, more preferably less than 0.5 ml. In a preferred embodiment, the volume of the jet of working fluid produced by the fluid delivery system is in the range of 0.1 to 0.4 ml. The fluid delivery system is preferably configured to deliver a jet of the working fluid to the nozzle at a static pressure in the range from 3 to 10 bar.

The handle preferably comprises a plurality of sections, which are preferably integrally formed with one another. The handle preferably includes a first section, or "grip section," that is held or gripped by the user during use of the implement. The grip section preferably comprises a user interface that is engaged by a user during use of the implement, for example to actuate delivery of working fluid from the fluid delivery system. The handle preferably further comprises a second section spaced from the grip section and along which the fluid reservoir moves relative to the handle. The second section of the handle is preferably located near the end of the handle, preferably the end of the handle closest to the nozzle, and may therefore be referred to as the "end section" of the handle. The end section preferably at least partially defines the end of the handle closest to the nozzle. When in its first position, the fluid reservoir preferably closes the end section of the handle so that it is not visible to a user of the appliance.

Preferably, the end section of the handle has a cross-section in a plane perpendicular to the longitudinal axis of the handle that is smaller than the cross-section of the grip section of the handle. This may allow the implement to have a relatively uniform appearance when the fluid reservoir is in its first position, for example when the fluid reservoir has an outer diameter that is the same as the outer diameter of the grip section of the handle. Alternatively or additionally, this may also allow the width of the fluid reservoir to be minimized for a given fixed capacity of the fluid reservoir.

The appliance preferably comprises means for inhibiting rotation of the fluid reservoir when the fluid reservoir is moved between the first and second positions. This may ensure that the fluid inlet port remains angularly aligned with a seal formed on the handle as the fluid reservoir is moved between the first and second positions. For example, the fluid reservoir may be movable along axially aligned grooves or recesses formed in the end section of the handle. In a preferred embodiment, the end section of the handle comprises a tubular outer surface and the fluid reservoir comprises a tubular inner surface surrounding the outer surface of the end section of the handle when the fluid reservoir is in its first position. The tubular outer surface of the end section of the handle preferably has substantially the same shape as the tubular inner surface of the fluid reservoir, which is preferably non-circular in a plane perpendicular to the longitudinal axis of the handle. In a preferred embodiment, the outer surface of the end section has an irregular shape in that plane: two opposing parallel surfaces and two opposing curved surfaces (defining a "racetrack" shape). However, the outer surface may have any desired shape, such as a regular or irregular polygon, that when mated with the inner surface of the fluid reservoir inhibits rotation of the fluid reservoir relative to the handle. The perforated wall of the fluid reservoir preferably has substantially the same shape as the inner wall of the fluid reservoir.

The handle preferably includes a seat for receiving the fluid reservoir when the fluid reservoir is in its first position. The base preferably includes an aperture through which the flexible conduit is pulled when the fluid reservoir is moved from its first position to its second position. The base is preferably located between the grip section and the end section of the handle, and is preferably arranged perpendicular to the longitudinal axis of the handle. Each of the base and the base of the fluid reservoir is preferably annular in shape. The base and the base of the fluid reservoir preferably have substantially the same outer diameter. Preferably, a seal is provided on the base to engage a seat of the fluid reservoir to inhibit leakage of working fluid from the fluid inlet port when the fluid reservoir is in its first position.

The base preferably has a partially enlarged cross-section compared to the grip section of the handle. The abutting outer surfaces of the base and the fluid reservoir preferably have substantially the same curvature such that the fluid reservoir and the base together appear as a single curved unit when the fluid reservoir is in its first position. In a preferred embodiment, the abutting outer surfaces of the base and the fluid reservoir preferably have a spherical or bulbous curvature.

As mentioned above, the fluid reservoir is preferably urged towards its first position in which its fluid inlet port is closed by the base of the handle. This may reduce the likelihood of the fluid reservoir moving away from its first position during use of the appliance if the fluid reservoir is accidentally knocked or otherwise impacted during use of the appliance. This, in turn, may reduce the risk of unwanted leakage of fluid from the fluid reservoir during use of the appliance.

When the fluid reservoir is moved from its first position towards its second position, the fluid reservoir moves away from the base and preferably towards the nozzle. The appliance preferably includes a stem extending between the handle and the nozzle. Preferably, at least a portion of the fluid reservoir extends around the rod when the fluid reservoir is in its second position. In a preferred embodiment, substantially only the base of the fluid reservoir continues to extend around the handle when the fluid reservoir is in its second position.

In order to prevent the fluid reservoir from becoming completely disengaged from the handle when it is moved away from the first position, the lever preferably comprises means for inhibiting movement of the fluid reservoir beyond the second position. The inhibiting means preferably comprises a stop member projecting from an outer surface of the stem. When the fluid reservoir reaches its second position, the stop member engages a portion of the fluid reservoir to inhibit movement of the fluid reservoir beyond the second position. The stop member may be arranged to engage an inner wall of the fluid reservoir, e.g. a wall defining a tubular inner surface of the fluid reservoir. In a preferred embodiment, the stop member is arranged to engage an outer wall of the fluid reservoir when the fluid reservoir is in its second position. As noted above, the outer wall of the fluid reservoir preferably has a generally spherical or globular curvature. The outer wall is preferably shaped such that a portion of the outer wall defines an aperture through which the rod passes when the fluid reservoir is in its second position. The stop member is preferably arranged to engage that part of the outer wall when the fluid reservoir is in its second position.

The lever is preferably removably connected to the handle. This allows the wand to be replaced, for example, when the nozzle becomes worn, to allow replacement wands of different sizes or shapes to be connected to the handle, or to allow different users to attach personal wands to the handle. Preferably, the stem forms an interference fit with the handle.

Preferably, the fluid reservoir is removably connected to the handle. The fluid reservoir may be removable from the handle, for example for replacement of the fluid reservoir. Preferably, the fluid reservoir can be removed from the handle only after the stem is removed from the handle.

In a second aspect, the present invention provides a fluid reservoir for a dental treatment appliance comprising a fluid port and a core for delivering a working fluid to the fluid port.

The appliance may be in the form of a dedicated interdental cleaning appliance for cleaning the spaces between the teeth of a user. Alternatively, the appliance may be in the form of a toothbrush with the additional function of improving interproximal cleaning by delivering working fluid to the interproximal spaces. Where the appliance is in the form of a toothbrush, the cleaning tool or wand preferably comprises a plurality of bristles. The bristles are preferably arranged around the nozzle and circumferentially around the nozzle. The plurality of bristles may be attached to a fixed section of the cleaning tool, which section is not movable relative to the handle. Alternatively or additionally, the plurality of bristles may be attached to a movable section of the cleaning tool, which section is movable relative to the handle.

In a preferred embodiment, the appliance comprises a brush unit comprising a bristle carrier and a plurality of bristles mounted on the bristle carrier, wherein the bristle carrier is movable relative to the handle. The implement includes a drive mechanism for driving movement of the bristle carrier relative to the handle. Preferably, the drive mechanism includes a drive unit (connected to the bristle carrier) and a drive unit (for driving the drive unit to move the bristle carrier relative to the handle). The drive unit is preferably located in the handle, and more preferably in an end section of the handle. The fluid reservoir preferably extends around at least a portion of the drive unit. In a preferred embodiment, the drive unit comprises a motor and the fluid reservoir extends around the motor of the drive unit. Housing the motor in the end section of the handle may reduce the number of parts of the implement housed within the grip section of the handle and thus may optimize the shape of the grip section for grasping by the user.

The drive unit may be arranged to move the bristle carrier relative to the stem. Alternatively, the drive unit may be arranged to move the rod, and thereby the bristle carrier, relative to the handle. The lever is preferably mounted on the transmission unit. The fluid reservoir preferably extends around at least a portion of the transmission unit.

The transmission unit is preferably in the form of a shaft which is moved, preferably vibrated, relative to the handle by a motor. The vibration frequency of the shaft is preferably in the range of 200 to 300 Hz. The motor preferably extends around the shaft such that the shaft vibrates relative to the handle when the motor is energized.

The transmission unit preferably defines part of a fluid delivery system. The shaft preferably includes an aperture defining a portion of the fluid delivery system.

The fluid delivery system preferably includes a handle conduit system and a cleaning tool conduit system for receiving fluid from the handle conduit system. The cleaning tool conduit system preferably includes at least one conduit for delivering a jet of working fluid to the nozzle. In a preferred embodiment, the stem includes an aperture that defines a fluid conduit of the cleaning tool conduit system. The handle tubing preferably includes a fluid inlet for receiving working fluid from the fluid port of the fluid reservoir and a plurality of conduits for conveying the working fluid between the fluid inlet, the pump and the fluid outlet of the handle. The plurality of conduits includes a flexible conduit for conveying fluid from the fluid inlet towards the pump, and a fluid outlet conduit for conveying a jet of working fluid from the pump to the fluid outlet. At least a portion of the fluid outlet conduit is preferably defined by the bore of the transmission unit and therefore preferably extends through the motor. At least a portion of the flexible conduit preferably extends from the fluid inlet to the pump adjacent an outer surface of the motor.

The above description of features relating to the first aspect of the invention applies equally to the second aspect of the invention and vice versa.

Drawings

Preferred features of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1(a) is a perspective view of the tooth cleaning implement from the front with the fluid reservoir in a first position, and FIG. 1(b) is a perspective view of the tooth cleaning implement of FIG. 1(a) from the rear;

FIG. 2(a) is a right side view of the appliance of FIG. 1(a), FIG. 2(b) is a front view of the appliance of FIG. 1(a), and FIG. 2(c) is a left side view of the appliance of FIG. 1 (a);

figure 3 schematically illustrates a fluid delivery system of the appliance;

FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2 (B);

FIG. 5 is a cutaway perspective view of a portion of a fluid reservoir;

FIG. 6(a) is a perspective view of the dental appliance with the fluid reservoir moved away from the first position, as viewed from the front, and FIG. 6(b) is a perspective view of the dental cleaning appliance of FIG. 6(a), as viewed from the rear; and

figure 7(a) is a perspective view of the dental appliance from the front with the fluid reservoir in the second position and figure 7(b) is a perspective view of the dental cleaning appliance of figure 7(a) from the rear.

Detailed Description

Figures 1(a) -2(c) show external views of an embodiment of a tooth cleaning implement 10. In this embodiment, the appliance is in the form of a hand-held appliance in the form of a power toothbrush with integrated components for dispensing working fluid for improved interproximal cleaning, for plaque removal or for tooth whitening.

The appliance 10 includes a handle 12 and a cleaning tool 14. The handle 12 comprises an outer body 16, preferably formed from a plastics material. The handle 16 includes a grip section 18 that is held by a user during use of the implement 10. The grip section 18 is preferably generally cylindrical in shape. The handle 12 includes a user operable button 20 located within an aperture formed in the body 16 for access by a user. Alternatively, the handle 12 may include a display positioned to be visible to a user during use of the appliance.

The cleaning tool 14 includes a shaft 22 and a head 24. The stem 22 is of an elongate shape that serves to space the head 24 from the handle 12 to facilitate user maneuverability of the appliance 10. In this embodiment, the head 24 of the cleaning tool 14 includes a brush unit 26 that includes a bristle holder 28 and a plurality of bristles 30 mounted on the bristle holder 28. However, in other embodiments, the cleaning tool 14 may be provided without the brush unit 26, such that the appliance is in the form of, for example, a dedicated interdental cleaning appliance for cleaning gaps in a user's teeth.

The cleaning tool 14 also includes a fluid reservoir 32 for storing working fluid and a nozzle 34 for delivering the working fluid to the mouth of a user during use of the appliance 10. The working fluid is preferably a liquid working fluid, in this embodiment water. As described in more detail below, the fluid reservoir 32 is mounted on the end section 36 of the handle 12 so as to extend around the end section 36 of the handle 12. In this embodiment it comprises a brush unit 26, which brush unit 26 extends at least partly around the nozzle 34.

The nozzle 34 forms part of a fluid delivery system 40 for receiving working fluid from the fluid reservoir 32 and for delivering a jet of working fluid to the mouth of a user during use of the appliance 10. Each jet of working fluid preferably has a volume of less than 1ml, more preferably less than 0.5 ml. The fluid delivery system 40 is schematically illustrated in fig. 3. The tip of the nozzle 34 includes a fluid outlet 42 through which a jet of working fluid is delivered to the mouth of the user. In general, the fluid delivery system 40 includes a fluid inlet 44 for receiving working fluid from the fluid reservoir 32. In this embodiment, the working fluid is a liquid working fluid, which is preferably water. The fluid delivery system 40 includes a pump assembly for drawing working fluid from the fluid reservoir 32 through the fluid inlet 44 and for delivering a jet of working fluid to the nozzle 34. The pump assembly is located within the grip section 18 of the handle 12 and includes a positive displacement pump 46 and a driver for driving the pump 46. The drive preferably includes a pump motor 48. A battery 50 for supplying power to the pump motor 48 is also located in the handle 12. The battery 50 is preferably a rechargeable battery.

A first conduit 52 connects the fluid inlet 44 of the fluid delivery system 40 to a fluid inlet 54 of the pump 46. A first one-way valve 56 is positioned between fluid inlet 44 and pump 46 to prevent water from flowing back from pump 46 to fluid reservoir 32. A second conduit 58 connects a fluid outlet 60 of the pump 46 to the nozzle 34. A second one-way valve 62 is located between pump 46 and nozzle 34 to prevent backflow of water into pump 46. The control circuit 64 controls actuation of the motor 48 and thus the pump motor 48 and control circuit 64 provide the driving force for driving the pump 46. The battery 50 supplies power to the control circuit 64. The control circuit 64 includes a motor controller that supplies power to the pump motor 48.

In this embodiment, the control circuit 64 receives a signal generated when a user presses a button located on the handle 12 of the appliance 10. Alternatively, or in addition, the control circuit 64 may receive signals generated by sensors located within the appliance 10, or from a remote control device (such as a display or personal device). For the sake of brevity, in the following description, the control circuit 64 receives a signal generated when the user operates the button 20.

The cleaning tool 14 is removably connected to the handle 12. Referring also to FIG. 4, the handle 12 includes a male connector, preferably in the form of a plug 66, which is received by a complementary female connector, preferably in the form of a female connector 68 of the cleaning tool 14. The plug 66 projects outwardly from the end section 36 of the handle 12, and preferably in a direction parallel to the longitudinal axis of the handle 12 (and more preferably collinear with the longitudinal axis of the handle 12).

The appliance 10 includes a drive mechanism for driving the shaft 22 and, thus, the movement of the bristle carrier 28 relative to the handle 12. The drive mechanism includes a transmission unit and a drive unit for driving the transmission unit to move the lever 22 relative to the handle 12. The drive unit includes a drive motor 70 located within the end section 36 of the handle 12. The control circuit 56 includes a motor controller that supplies power to a drive motor 70. The button 20 may also be used to activate and deactivate the drive motor 70 to start and subsequently stop the cleaning period, for example, by depressing the button 20 a predetermined number of times within a preset time period. Alternatively, a separate button (not shown) may be provided for activating and deactivating the drive motor 70.

The transmission unit comprises a shaft 72 which is driven by the drive unit to oscillate relative to the handle 12. The plug 66 is connected to the shaft 72 and is preferably integrally formed with the shaft 72. The drive unit is preferably arranged to oscillate the shaft 72 such that it oscillates about the longitudinal axis of the handle 12, preferably at a frequency in the range of 200 and 300 Hz. In this embodiment the drive motor 70 is arranged to rotate the shaft 72 about the longitudinal axis away from the central position by an angle which is preferably in the range from 5-15 deg., and in this embodiment 10 deg.. The drive unit further comprises a spring member 74 for engaging the shaft 72 to return the shaft 72 to its central position. The spring member 74 includes a pair of torsion springs 76 on opposite sides of the shaft 72, each torsion spring having a first end engaged with the shaft 72 and a second end attached to a support ring 78, the support ring 78 being connected to the handle 12 or otherwise held in a fixed position relative to the handle 12.

The handle 12 includes a base 80 for receiving the fluid reservoir 32. The base 80 is located between the grip section 18 and the end section 36 of the handle 12. The first conduit 52 of the fluid delivery system 40 includes a flexible section 82 that extends through an aperture 84 formed in the base 80 to connect to a fluid port 86 of the fluid reservoir 32. Thus, the flexible section 82 of the first conduit 52 travels along the outside of the drive motor 70, adjacent the outer surface of the drive motor 70, toward the pump 46.

The second conduit 58 (which connects the pump 46 to the nozzle 34) includes a handle conduit section located within the handle 12 and a cleaning tool conduit section located within the cleaning tool 14. The handle conduit section extends from the fluid outlet 60 of the pump 46 to a handle fluid outlet 88 at the end of the plug 66. The handle conduit section includes an outlet section 90 that is defined by the bore of the shaft 72, and the outlet section 90 is routed by the drive motor 70 toward the cleaning tool 14. Thus, the working fluid travels outside of the drive motor 70 in a first direction toward the pump 46, and then passes through the drive motor 70 in a second direction, opposite the first direction, away from the pump 46. The cleaning tool conduit section extends from a cleaning tool fluid inlet port defined by the female connector 68 of the cleaning tool 14 toward the nozzle 34. The cleaning tool conduit section comprises a conduit defined by a bore of the stem 22 of the cleaning tool 14.

The fluid reservoir 32 preferably has a capacity in the range of 5 to 50ml, and in this embodiment has a capacity of 10 ml. The fluid reservoir 32 includes a base in which a fluid port 76 is formed. The base 92 is annular in shape and extends outwardly from a tubular inner wall 94 of the fluid reservoir 32. The inner wall 94 of the fluid reservoir 32 has a tubular inner surface that surrounds the outer surface of the end section 36 of the handle 12. Each of these surfaces preferably has a non-circular cross-section perpendicular to the longitudinal axis of the handle 12. In this embodiment, each of these cross-sections has a "racetrack" shaped cross-section, so long as the cross-sectional shape includes two parallel opposing sides and two curved opposing sides.

The fluid reservoir 32 also includes an outer wall 96 that extends from an edge of the base 92 to an end of the inner wall 94 distal from the base 92. At least a portion of the outer wall 96 of the fluid reservoir 32 is preferably transparent to allow a user to view the interior of the fluid reservoir 32 and thereby assess whether the fluid reservoir 32 needs to be replenished before the intended use of the appliance 10. The outer wall 96 preferably has a symmetrical shape about the longitudinal axis of the handle 12. The outer wall 96 preferably has a curved shape, more preferably a convex curved shape, but alternatively the outer wall 96 may have a polygonal or faceted shape. In this embodiment, the outer wall 96 has a spherical curvature. The abutting portions of the outer side surface of the base 80 also have a similar spherical curvature, such that the fluid reservoir 32 and the base 80 together appear to the user as a single spherically curved unit, as shown in fig. 2(a) -2 (c). The end of the outer wall 96 remote from the base 92 defines a circular aperture 98 through which the shaft 72 of the drive mechanism passes.

Referring to fig. 4 and 5, the fluid reservoir 32 includes a perforated wall 100 that divides the fluid reservoir 32 into an upstream chamber 102 and a downstream chamber 104. Each of the upstream chamber 102 and the downstream chamber 104 is annular, with the upstream chamber 102 surrounding the downstream chamber 104. The porous wall 100 is tubular in shape and has a shape that is substantially the same as the shape of the inner wall 94. The base includes a fluid inlet port 106, and the fluid reservoir 32 is refilled with working fluid through the fluid inlet port 106. The fluid inlet port 106 is positioned such that, as described in more detail below, working fluid enters the upstream cavity 102 from the fluid inlet port 106. The fluid port 86 is positioned to receive working fluid from the downstream chamber 104. In this embodiment, the fluid port 86 extends partially about the longitudinal axis of the handle 12, preferably at least 180 °.

The downstream chamber 104 also includes a core 108 for delivering working fluid to the fluid port 86. The core 108 is annular in shape and, in this embodiment, substantially fills the downstream cavity 104. The core 108 is preferably formed of a sponge or Foam material, and in this embodiment, is formed of a polyurethane sponge material, such as the Capu-Cell available from Foam Sciences^TMAnd (3) foaming. The core 108 acts to transport the working fluid toward the fluid ports by capillary action, but the core 108 may be configured to provide additional benefits. For example, the core 108 may include a material that is soluble in the working fluid (which is preferably water) stored in the fluid reservoir 32.

The dissolvable material may comprise a water soluble phosphate salt. The phosphate material may be in the form of a phosphate glass, such as sodium calcium phosphate or sodium calcium silicophosphate, which will slowly dissolve in the water stored in fluid reservoir 32 to release minerals such as calcium phosphate, sodium phosphate, and silicon dioxide. Calcium ions in the released material may be beneficial in re-calcifying cavities or lesions formed in the enamel of a user's teeth, while silica is widely used in toothpaste for stain removal.

The dissolvable material may comprise a dissolvable matrix impregnated with solid particles that disperse in the stored working fluid as the matrix dissolves into the working fluid. The solid particles may include, for example, mica or glycine particles that are delivered to the user's teeth in a jet of working fluid, e.g., to help remove material located in the user's interdental spaces, or to disrupt the plaque layer formed on the user's teeth. The solid particles may comprise sodium calcium phosphate glass particles, which may fill channels present in sensitive teeth, or titanium dioxide particles.

The dissolvable matrix may comprise inorganic or organic materials such as acrylates or vinyl polymers. Such materials may also be provided without solid particles, and may be surface active materials, which may aid in the tooth cleaning process. The organic polymeric material may be functionalized with, for example, lauryl sulfate groups to improve the cleaning process, or to deliver fluoride or chelating agents such as EDTA (ethylene diamine tetraacetic acid). The dissolvable material may also include an organic polymer that prevents the accumulation of scale or microorganisms in the fluid reservoir 32. The dissolvable material may also include other materials, such as fluoride for improved tooth cleaning, or antimicrobial materials. For example, the dissolvable material may include silver particles having antimicrobial properties.

When replenishing the fluid reservoir 32 through the fluid inlet port 106, the fluid reservoir 32 is movable along the end portion 36 of the handle 12 between a first position (as shown in fig. 1(a) -2 (c)) in which the fluid inlet port 106 is closed by the base 80, and a second position (as shown in fig. 7(a) and 7 (b)) in which the fluid inlet port 106 is exposed to allow the fluid reservoir 32 to be replenished. Fig. 6(a) and 6(b) show the fluid reservoir 32 intermediate the first position and the second position.

In this embodiment, the fluid reservoir 32 is slidable along the end section 36 of the handle 12 as it moves between the first and second positions. Rotation of the fluid reservoir 32 relative to the handle 12 is inhibited by using a non-circular cross-sectional shape for the outer surface of the end section 36 of the handle 12 and the inner surface of the inner wall 94 of the fluid reservoir 32. When the fluid reservoir 32 is moved from the first position to the second position, the flexible section 82 of the first conduit 52 is pulled through the aperture 84 formed in the base 80, thus inhibiting rotation of the fluid reservoir 32 ensures that the flexible section 82 is pushed fully back through the aperture 84 when the fluid reservoir 32 is returned to its first position. Inhibiting rotation of the fluid reservoir 32 also ensures that the fluid inlet port 106 remains angularly aligned with any seals formed on the base 80 to prevent leakage of working fluid from the fluid inlet port 106.

As the fluid reservoir 32 moves toward its second position, the base 92 of the fluid reservoir 32 moves along the end portion 36 of the handle 12 toward the stem 22. When in its second position, only the base 90 of the fluid reservoir 32 still extends around the end portion 36 of the handle 12; now, a portion of the fluid reservoir 32 extends around the rod 22. To prevent the fluid reservoir 32 from becoming completely separated from the handle 12 when it is moved away from the first position, the appliance 10 includes a stop member 110 that engages the fluid reservoir 32 when the fluid reservoir is in its second position to inhibit movement of the fluid reservoir 32 beyond its second position. A stop member 110 projects from the stem 22 and is arranged to engage a peripheral portion of the outer wall 96 that defines the aperture 98 through which the shaft 72 passes 98.

To fill the fluid reservoir 32 with working fluid (water in this embodiment), the user flips the implement 10 from the orientation shown in fig. 1(a) -2(c) and pulls the fluid reservoir 32 toward the head 24 of the implement 10 so that the fluid reservoir 32 moves to its second position. The user may place the exposed fluid inlet port 106 under the spout of the faucet and then open the faucet so that water enters the fluid reservoir 32 from the spout through the fluid inlet port 106. Because the outer wall 96 of the fluid reservoir 32 is transparent, a user may view the filling of the fluid reservoir 32. When the fluid reservoir 32 is full, the user returns the fluid reservoir 32 to its first position and then to the orientation shown in fig. 1(a) -2(c) for use.

To operate the appliance 10, the user turns on the appliance 10 by pressing the button 20, which action is detected by the control circuit 64. The control circuit 64 activates the drive motor 70 to move the brush unit 26 relative to the handle 12. When the button 20 is pressed again, a stream of water is emitted from the nozzle 34. Control circuitry 64 activates pump 46 to cause a volume of water to flow from the fluid chamber of pump 46 to nozzle 34, and to replenish the fluid chamber by drawing a volume of water from fluid reservoir 32. The core 108 increases the likelihood that working fluid will be drawn from the fluid reservoir 32 during use of the appliance 10, wherein the appliance 10 can be held in a variety of different orientations for treating the oral cavity. This continues until the user turns off the device 10 using the button 20 or the fluid reservoir 32 is depleted.

To replace the fluid reservoir 32, the user first pulls the rod 22 out of the plug 66. The user may then slide the fluid reservoir 32 to its second position, detach the flexible section 82 of the first conduit 52 from the fluid port 86, and then slide the fluid reservoir 32 from the end section 36 of the handle 12.

Claims

1. A dental treatment appliance comprising:

a fluid reservoir for storing a working fluid; and

a fluid delivery system for receiving the working fluid from the reservoir and for delivering the working fluid to the oral cavity of the user;

2. The appliance of claim 1, wherein the core is formed of an absorbent sponge material.

3. The appliance of claim 1 or claim 2, wherein the core is formed from a water-absorbing material.

4. The appliance of any preceding claim, wherein the core is formed of polyurethane.

5. The appliance of any preceding claim, wherein the core comprises a material dissolvable in the working fluid.

6. The appliance of claim 5, wherein the dissolvable material comprises a phosphate material.

7. The appliance of claim 6, wherein the phosphate material is phosphate glass.

8. The appliance of claim 6 or 7, wherein the phosphate material is one of calcium sodium phosphate or calcium sodium silicophosphate.

9. The appliance of any of claims 5 to 8, wherein the dissolvable material comprises a dissolvable matrix impregnated with solid particles that disperse within the stored working fluid when the matrix dissolves into the working fluid.

10. The appliance of claim 9, wherein the solid state particles comprise at least one of mica particles, glycine particles, titanium dioxide particles, and sodium phosphate glass particles.

11. The appliance of any preceding claim, wherein the core comprises an antimicrobial coating.

12. The appliance of claim 11, wherein the antimicrobial coating is one of a silver coating, a silver zeolite coating, and a silver nitrate coating.

13. The appliance of any preceding claim, wherein the core comprises activated carbon.

14. The appliance of any one of the preceding claims, wherein the fluid reservoir comprises a perforated wall dividing the fluid reservoir into an upstream cavity and a downstream cavity, and wherein the core is located in the downstream cavity.

15. The appliance of claim 14, wherein the core substantially fills the downstream cavity.

16. An appliance according to claim 14 or 15, wherein the upstream chamber is substantially free of sponge material.

17. An appliance according to any of claims 14 to 16, wherein the upstream chamber surrounds the downstream chamber.

18. The appliance of any of claims 14 to 17, wherein each of the upstream and downstream cavities is annular in shape.

19. The appliance of any of claims 14 to 18, wherein the fluid reservoir comprises a base extending between inner and outer walls of the fluid reservoir, and wherein the fluid port is formed in the base.

20. An appliance according to any of claims 14 to 19, wherein the fluid reservoir comprises a fluid inlet port, and wherein the upstream chamber is arranged to receive working fluid directly from the fluid inlet port.

21. The appliance of claim 20, wherein the fluid reservoir is movable relative to a fluid delivery system to expose the fluid inlet port to allow replenishment of the fluid reservoir.

22. The appliance of any of claims 14 to 21, wherein the perforated wall is annular in shape.

23. An appliance according to any preceding claim, comprising a handle and wherein the fluid reservoir extends around the handle.