Dentifrice dispensing electrical toothbrush with integrated dispensing platform and self sealing spout

Dentifrice dispensing electrical toothbrush comprising a driver-pump head with a dispensing platform, a replaceable brush unit and a handle having a battery and a cartridge containing dentifrice material. The replaceable brush unit includes a oscillatory brush element and a brush element having a circular or an elongated spout opening as well as a snap-on mounting bracket for fastening to the driver-pump head. The dispensing platform contains a flow channel and a self-sealing spout to prevent drying of the dentifrice material at the spout. The self-sealing spout opens and closes automatically during a pumping action. The brush element with a spout opening is detachably mounted over the spout fixed on the dispensing platform to allow for brush oscillation around the spout and receive the dentifrice material dispensed from the flow channel. Different drive mechanisms are used to impart rotary, lateral or longitudinal oscillation on a brush element in a brush unit.

BACKGROUND

It has been recognized through clinical tests that an electrical toothbrush is more effective in removing plaque and preventing gum disease than a conventional manual toothbrush. It is also well known that toothbrush bristles should be replaced on a regular basis since bristle harbor germs after a period of use. A large number of conventional disposable brushhead include a neck portion, which is a waste of material. Besides, many types of electrical toothbrush use high power vibration of neck or handle portion to achieve oscillation of brushhead, which requires high battery power. Furthermore, dispensing dentifrice material to an electrical toothbrush presents great challenges to the handicapped as an electrical toothbrush is much bulkier than a manual toothbrush for applying dentifrice material. Currently there is no electrical toothbrush commercially available that can dispense dentifrice material from its handle to brush head. For ergonomic and portability, an electrical toothbrush needs to contain and dispense dentifrice material easily with one hand to its bristles for brushing. Moreover a conventional spout for dispensing the dentifrice material requires manual capping, which is often ignored resulting in clogging and pumping failures. These shortcomings necessitate an electrical toothbrush that can dispense dentifrice material with a spout that can automatically seal itself to prevent drying of the dentifrice material.

FIELD OF INVENTION

The present invention relates to dentifrice dispensing electrical toothbrush having replaceable brush elements, an oscillation mechanism and a cartridge containing dentifrice material.

OBJECTS OF THE INVENTION

It is the objective of the present invention to provide a dentifrice dispensing electrical toothbrush using a permanent self-closing spout to dispense dentifrice material to a brush element, minimizing both the amount of disposable brush material and the battery power for the oscillation of a brush element.

PRIOR ART

U.S. Pat. No. 6,434,773 by Kuo describes a dentifrice dispensing electrical toothbrush having a flow channel to dispense dentifrice material to two replaceable oscillating brush elements. The dentifrice material is pumped from a cartridge to a spout opening at the base of one brush element. The two brush elements are detachably mounted on two posts on the platform of the brushhead neck through the use of a snap-on mounting bracket. The oscillating motion of the brush elements is imparted by the engagement of notches at the bottom of the brush elements to an end-cap which is attached to a shaft driven by a motor. Although the two brush elements are replaceable, their mounting on two posts which are fixed on the neck platform requires significant pulling force to detach them from the posts, not an easy task for general users. Moreover, the shaft's end-cap is situated in a restricted recess area between two posts, which is not accessible for cleaning as needed between replacements of the brush elements. Additionally, the spout opening is not self-closing, therefore, exposing the dentifrice material to ambient air causing drying of the dentifrice material and resulting in clogging of the flow channel leading to pumping failures.

U.S. Pat. No. 6,735,803 by Kuo provides an electrical dentifrice dispensing ( ) having a replaceable bristle unit consisting a rotary brush element and a stationary brush element which has a spout opening for the flow of dentifrice material. A linkage is used to convert the rotation of the drive shaft to a planar oscillation that enables a compact drive head configuration. The dispensing of dentifrice material is accomplished by using a rotary solenoid for actuating an internal button that applies pumping pressure to the dentifrice material. As a benefit to arthritis suffers, no external squeezing action is involved. Again, the ( ) provides neither open access to the shaft engagement area for cleaning nor self-closing spout for preventing drying of dentifrice material.

To resolve brushhead cleaning problem at replacement, U.S. Pat. No. 6,902,337 by Kuo describes a dentifrice dispensing electrical toothbrush using a replaceable dual-channel brush element. The dual-channel brush element has a first channel for housing a drive shaft for bristle oscillation and a second channel for dispensing the dentifrice material. The brush element is mounted on the dual-channel connector of the brush handle, which contains a drive mechanism and a pumping mechanism that dispenses dentifrice material from a cartridge in the handle. No shaft cleaning is needed at the replacement of the brushhead but the whole dual-channel brushhead is discarded at replacement that is an expensive waste of material.

U.S. Pat. No. 7,789,583 by Kuo describes manual and electrical pump ( )es using a slit valve for preventing drying. The slit valve, which is made of rubber or elastomeric material, prevents backflow and drying of the dentifrice material at the spout opening. However, the inclusion of the rubber slit-valve in otherwise plastic dual channel brushhead makes the whole bulky disposable brushhead a non-recyclable item.

To impart vibration to a brushhead without using a rotary brush element, U.S. Pat. No. 7,877,832 by Reinbold describes a powered ( ) comprising a handle containing a motor and a power supply, and a brush element including a neck which is flexibly and resiliently connected to the handle. The motor and a transmission means are pivotally mounted within the handle and use the vibration of the handle to oscillate the brush element-and-neck. The method has disadvantages of replacing the whole brush element-and-neck and requiring extra motor power to vibrate the handle in order to oscillate the brush element-and-neck. It is a waste of neck material and battery power.

Therefore, it is desirable to have an electrical toothbrush that has a slit valve mechanism for preventing drying of dentifrice material and not part of a disposal brushhead. It is desirable to use a disposable brush unit without having a conventional neck portion. It is also desirable to impart oscillation of brush elements without causing vibration to the neck and handle of an electrical toothbrush to save battery power. Furthermore, it is desirable to have common brush unit and driver-pump head configurations for different types of brush oscillation.

SUMMARY OF THE INVENTION

A dentifrice dispensing electrical toothbrush is provided with a driver-pump head having an extended dispensing platform attached with a slit spout, a replaceable brush unit and a refillable cartridge for storing dentifrice material. A replaceable brush unit consists of only brush elements and a mounting bracket without a conventional neck portion. The driver-pump head including the dispensing platform and the slit spout is for repeated permanent uses. The brush unit is equipped with snap-on fastening arms for conveniently attached to and detached from the driver-pump head. A brush element having a spout opening is mounted over the slit spout to receive the dentifrice material from the flow channel in the dispensing platform. The slit spout is self-sealing to prevent drying of the dentifrice material at the spout. An elastic compressible button is used to apply pumping pressure. The slit spout is forced to open by the exiting dentifrice material and to close by the vacuum force created when the pumping pressure is released. The vacuum force also causes the piston in the cartridge advance to push the dentifrice material into the pumping chamber through a one-way check valve in the pump head.

Various configurations of brush unit and drive mechanism for the oscillation of brush elements are given. For a brush unit having two rotary brush elements with one having circular spout opening, drive notches of both brush elements are directly engaged with a drive shaft undergoing limited angular oscillation. For a brush unit having one rotary brush element and one translational element having an elongated spout opening, the longitudinal oscillation of the translational element is driven by a linkage connected to the rotary brush element. For a brush unit having a single unitary brush element with a spout opening elongated in lateral direction, the lateral oscillation of the brush element is guided by parallel side guides on the mounting bracket for free sliding support. For a brush unit having a single unitary brush element with a longitudinal spout opening, the longitudinal oscillation is achieved by a drive mechanism using bevel gears with a biased wheel and a linkage bar to cause axial oscillation of the drive shaft to impart oscillation to the unitary brush element. In all these brush unit and drive configurations, only the brush elements are oscillated while the mounting bracket and the handle are non-oscillatory to save battery power.

DESCRIPTIONS OF THE INVENTION

Throughout the following detailed descriptions, same reference numerals refer to the same elements in all figures.

The structure and function of the dentifrice dispensing electrical toothbrush of the present invention are described in details as follows. As shown inFIGS. 1a,1b, a dentifrice dispensing electrical toothbrush4of present invention includes handle8, driver-pump head12and brush unit16.FIG. 1ashows dentifrice dispensing electrical toothbrush4un-assembled with brush unit16being detached from driver-pump head12. Handle8includes housing wall22, battery70, and cartridge108which is a reservoir storing dentifrice material.

Driver-Pump head12includes side wall20, driving chamber24, and pumping chamber28. Pumping chamber28includes side opening36attached with actuator40, inlet connector44and dispensing platform32, which has flow channel48attached with spout52. Both inlet connector44and dispensing platform32are supported by sidewall20. Driving chamber24includes motor56, cam assembly60and a shaft channel64including a drive shaft68. The motor is powered by battery70positioned within the handle. Referring toFIG. 2, drive shaft68and motor56are connected by cam assembly60, which imparts an oscillating motion to the drive shaft. Motor drives bias wheel72, which is connected to motor output shaft76. An oval-shaped cam80is connected to top end84of drive shaft68. End cap88is attached to top end84of the drive shaft with tab92extending radially outward from the central longitudinal axis96of the drive shaft. When connected to the drive shaft as shown inFIG. 2, tab92oscillates with the drive shaft and imparts oscillating motion to brush elements138and140. The off-center position of a biased wheel controls the amplitude of the angular oscillation of the drive shaft, which in turn limits the amplitude of the rotary oscillation of the brush element being driven. Referring toFIG. 1a, bearing104is used for supporting drive shaft and for preventing cleaning water into the shaft channel64. Dentifrice cartridge108having piston112is attached to inlet connector44. OnFIG. 1a, cartridge108includes cylindrical tube116and piston112. Cylindrical tube116has interior threads on annular wall extension at top opening end126. Piston112having flexible upper annular rim120and lower annular rim124is inserted into cylindrical tube116through bottom opening end128of the cartridge to provide slidable sealing of the dentifrice material inside the cartridge. Each component and its function will be further described in detail in the following sections.

Pumping Action

FIG. 1bshows assembled dentifrice dispensing electrical toothbrush4having brush unit16mounted on driver-pump head12. Dentifrice material132is pumped from pumping chamber28, through flow channel48and spout exit136, to bristles172of brush element140. A pumping force is applied to the pumping chamber by depressing on actuator40. In a preferred embodiment, actuator40is an elastic compressible button and its location in the driver-pump head with respect to the handle is convenient to apply the pumping pressure in one hand operation. When the pumping force is released, the elastic compressible button returns to its original position automatically due to the resiliency of its rubber material. The vacuum force created inside pumping chamber28by releasing of the actuator causes dentifrice material132to flow from cartridge108through one way check valve110and into the pumping chamber to replace the dentifrice material removed from the pumping chamber. The exiting of dentifrice material from cartridge108causes corresponding advancement of piston112toward the top opening126of the cartridge. As shown inFIG. 1b, the flow channel48provides the flow path for dentifrice material from the pumping chamber28to the brush element140.

Dispensing Platform and Slit Spout

In the present invention a slit spout is fixed to the dispensing platform, which is an extended portion of the driver-pump head.FIG. 1bshows dispensing platform having flow channel48extended from the pumping chamber28and outlet opening50. In a preferred embodiment spout52is of slit configuration. Slit spout52has tubular wall53with cross-slits55at its apex. A slit spout is preferably made of thermoplastic elastomer material for resiliency by dip or injection molding and the cross slits are formed by slicing action of a sharp blade. A slit-spout has multiple flappers forming a normally closed dome-shaped surface when the cavity is empty or not under pressure. Each flapper is a curved triangular valve segment extending from tubular wall with tip of each valve segment intercepting at the apex when the slit spout is closed. Each flapper segment can be bent outward like a cantilever beam such that slit spout52is at open state at exit136as shown inFIG. 2b. The slit-spout is forced to open by exiting dentifrice material under the pumping pressure when the elastic compressible button40is depressed as shown inFIG. 1b. The slit spout closes after the elastic button is released. The slit length, wall thickness and the elastic modulus of the spout material are designed to ensure closing of the slit spout by the resiliency and the vacuum force created when the pumping force is released. Slit spout is attached to the outlet opening50by adhesive means. Alternatively a slit valve may be designed with a flexible flange (not shown) at its base for insertion into the flow channel48where the flange is latched beneath the outlet opening50for securing the slit spout in place.

Brush Unit Assembly

A brush unit of the present invention is detachably mounted on the dispensing platform32. Brush unit16as shown inFIG. 1aincludes two rotary brush elements138and140. First rotary brush element has base144having its frontside attached with bristles and its backside attached with notch extension152with notch156(shown inFIG. 2). Referring toFIG. 1a, the center of the backside also has a recess166which is shaped to mate with post164on the mounting bracket168for free rotation. In addition to bristles, base56of second brush element140has spout opening180for detachably mounting over outlet opening wall184on the dispensing platform32to receive the dentifrice material dispensed from the slit spout. Notches156,188are mounted on top of tab92. A limited angular oscillating motion of tab causes brush elements138and140to oscillate freely around post164and outlet opening wall184, respectively. Furthermore, as will be shown in later sections, sidewall of each brush element has groove for accommodating a retention pin on the mounting bracket for maintaining the height of the brush element from the dispensing platform for free oscillation. The width of each groove is sufficient to allow for the range of the angular oscillation of each brush element.

For fastening the bristles elements to the dispensing platform, a mounting bracket is used. Detailed descriptions of a mounting bracket of the present invention will be given in later sections.

Rotary and Translational Brush Elements

In addition to the configuration for the oscillation of two rotary brush elements, the driver-pump head having a dispensing platform and a slit spout is applicable to a brush unit having a rotary brush element and a translational brush element.FIG. 3, without including a mounting bracket, shows drive shaft68and a bottom view of linkage250between rotary brush element254having notch268, and translational brush element258having spout opening264elongated in the longitudinal direction, which is aligned in the axial direction of drive shaft68. When tab92of end cap88of the drive shaft68is engaged with the notch268of the rotary brush element254, the angular oscillation272of the drive shaft imparts linear oscillation276of the translational brush element258. As the translational brush element oscillate, the spout opening moves up and down with respect to a slit spout which is fixed to a dispensing platform as described inFIG. 1a.

Unitary Brush Unit with Lateral Spout Opening

The driver-pump head having a dispensing platform and a slit spout is also applicable to a unitary brush element structure, which has one base combining the features of drive notch and spout opening in one brush element. In a unitary brush element configuration, the oscillation of the brush element can be either in lateral or in longitudinal direction as will be described in the following sections.

FIGS. 4a,4b,4cshow un-assembled brush unit300detached from dispensing platform348. The structure of the unitary brush unit300is for oscillating in the lateral direction, which is perpendicular to a drive shaft as described previously.FIG. 4ashows unitary brush element304having notch312positioned under and at the center of base308and a lateral spout opening316elongated perpendicular direction to a drive shaft that is engaged with notch312. Mounting bracket320for unitary brush element304is shown inFIG. 4b. The mounting bracket320comprises base324having notch opening328and spout opening332, two parallel side guides336and a pair of fastening arms340. The notch opening328is for inserting notch312of the unitary brush element316through base324to engage with the end cap344of the dispensing platform348as shown inFIG. 4c. The spout opening332is for inserting slit spout352through base324and through the elongated spout opening316of the brush element as shown inFIG. 4d, which shows the mounting of the unitary brush element304and the mounting bracket320on the dispensing platform348. The parallel side guides336are for sliding-fit with sidewalls356of the brush element304for free lateral oscillation. Side guide336has pinhole360for accommodating a retention pin364, which is inserted into groove368on sidewall356of brush element304. The engagement of the pair of retention pins364and grooves368, as shown inFIG. 4dis for maintaining free lateral oscillation of the brush element304on top of the mounting bracket320by drive shaft68.

Mounting Bracket and Fastening Arms

The use of fastening arms as described in U.S. Pat. No. 6,434,773 is applicable to the mounting bracket of the present invention. It is briefly described as follows. Referring toFIGS. 4a,4band4c, mounting bracket320for the brush element304is attachable to and detachable from the dispensing platform348by squeezing on upper ends of a pair of fastening arms340on opposite sidewalls of the mounting bracket320. The lower end of each fastening arm340has an inward protruding rib372which detachably engages a recess376on sidewall380of the dispensing platform348. The fastening arms are designed to function as a pair of cantilever beams in a manner inward deflections of their upper ends toward each other causes outward deflections of their lower ends, such that the ribs are detached from the dispensing platform.

With unitary brush element and the mounting bracket latched on the dispensing platform,FIGS. 5a,5band5cshow different lateral positions of the unitary brush element304with respect to side guides336′, fastening arms340′ and slit spout352′ in the dispensing platform348′. Specifically,FIGS. 5a,5band5cshow the spout opening316at the middle position, moved to the right and to the left of the slit spout′352′, respectively, when the brush element308is in oscillation motion. In order for the space above the spout area to have bristle coverage or to reduce the void, tufts of bristles around the spout opening are tilted toward the spout opening.FIG. 5dshows angled tufts390of bristles in brush element304surrounding the spout opening316being tilted toward the center of the spout opening316.

Unitary Oscillatory Brush Element

In another unitary brush unit configuration, a brush element for longitudinal oscillation has its spout opening elongated in the longitudinal direction of the brush element.FIGS. 6a, b, candFIGS. 6a,6b,6cshow un-assembled unitary brush unit400detached from dispensing platform448. The structure of the unitary brush unit400is for oscillating in the longitudinal direction of the brush element404.FIG. 6ashows unitary brush element404having notch412under its base408and a longitudinal spout opening416, which is an elongated slot oriented in the axial direction of a drive shaft that is engaged with notch412. Mounting bracket420for the unitary brush element404is shown inFIG. 6b. Mounting bracket420comprises base424having notch opening428, spout opening432, and two parallel side guides436which function as fastening arms. Similarly, notch opening428is for inserting notch412of the unitary brush element404through base424to engage with the top end444of drive shaft468. The top end444is shaped as a bent tab as shown inFIG. 6cto engage with notch412to impart notch oscillation. The spout opening432is for inserting slit spout452through the bracket base424and the elongated spout opening416of the brush element404as shown inFIG. 6d. The parallel side guides436are for sliding-fit with the sidewalls456of brush element404for guiding free longitudinal oscillation. Side guide436has pinhole460for accommodating a retention pin (not shown), which is inserted into groove470on sidewall456of the brush element404. The engagement of the pair of retention pins and grooves is for maintaining free lateral oscillation of the brush element on top of the mounting bracket. Mounting bracket420for brush element404is attachable to and detachable from the dispensing platform448by squeezing on upper ends of fastening arms436on opposite sidewalls of the mounting bracket420, whose functions have been described previously.

In one embodiment, the longitudinal oscillation of drive shaft468is achieved by a means of bevel gears472, biased wheel476and linkage mechanism480in connection with motor484as shown inFIG. 6d. When motor484is energized, the change of rotation of bevel gears472causes the biased wheel to swing the linkage bar that in turn causes the drive shaft468to move forward and backward in oscillation. The reciprocating motion of the drive shaft causes the brush element404to oscillate in longitudinal direction accordingly. The drive shaft is being supported at the top end with bearing488preventing cleaning water or foreign media getting into the shaft channel. The bearing provides free sliding support to the shaft without transmitting shaft oscillation to the shaft channel, the driving chamber and the handle of an electrical toothbrush of the present invention.

The structure of a unitary brush unit and its associated drive mechanism as described above are applicable to an electrical toothbrush. An electrical toothbrush does not contain dentifrice material.FIG. 7shows an electrical toothbrush500of the present invention having a lateral oscillation brush element504. The brush element504has notch512under its brush base508with notch orientation in the longitudinal direction of the brush element504. Mounting bracket516has bracket base520having a notch opening524, two parallel side guides528and a pair of fastening arms532. The parallel side guides are for sliding-fit with the sidewalls of the brush element for free lateral oscillation. Each side guide has a pinhole for accommodating retention pin536, which is inserted into groove540on a sidewall of the brush element. The notch opening524is for inserting notch512of the brush element504through bracket base520to engage with end cap544of drive shaft548. The drive shaft is contained inside neck having cylindrical wall552, which is extended from the handle. The angular oscillation of the drive shaft as generated by a cam and biased wheel mechanism as described previously imparts lateral oscillation of the brush element504without causing the vibration of the neck and handle of an electrical toothbrush of the present invention.

Furthermore,FIG. 8shows an electrical toothbrush600having a longitudinal oscillation brush element604. The brush element has notch612under its base608with notch orientation in the lateral direction of the brush element. Mounting bracket616has base620having notch opening624, two parallel side guides632, which also function as a pair of fastening arms. The parallel side guides are for sliding-fit with the sidewalls of the brush element for guiding free longitudinal oscillation. The reciprocating oscillation of the drive shaft648as driven by bevel gears, with a biased wheel and linkage mechanism similar to that previously described inFIG. 6d, imparts longitudinal oscillation of the brush element604without causing the vibration of the neck and handle of an electrical toothbrush of the present invention.

Brush Unit with Pushbuttons

In the preceding brush unit configurations, a brush unit is equipped with a pair of fastening arms attached on the opposite sidewalls of its support bracket. In another embodiment of the present invention, a brush unit is mounted onto a dispensing platform by means of a pair of pushbuttons.

For simplicity of descriptions, a brush unit having a rotary and a stationary brush element is illustrated inFIGS. 9aand9b. Brush unit716as shown inFIGS. 9a,9bincludes rotary brush elements738and stationary brush element740. Rotary brush element738has its front attached with bristles748and its backside attached with notch extensions752. The center of the backside has a recess760which is shaped to mate with post764on support bracket768for free rotation. In addition to bristles772, brush element740has spout opening780for detachably mounting over spout784on the dispensing platform732, which is shown inFIGS. 9c,9d, to receive the dentifrice material dispensed from the slit spout.

The function and configuration of the dispensing platform732are similar to that described previously with its flow channel746being in communication with a dentifrice cartridge and shaft770being driven by a motor in a handle as shown inFIGS. 1a,1b. Notch extensions752forms notches mounted on top of tab792, which is attached to the top end of drive shaft770. A limited angular oscillating motion of tab792causes brush element738to oscillate freely around post764. For fastening brush unit716onto dispensing platform732, the brush unit has a pair of pushbutton posts754,758attached to the backside of support bracket768. The pushbutton posts, each having a pushbutton head, are positioned to mate with receptacles782,786, which are attached to shaft channel wall790of dispensing platform732. The receptacles are positioned on each side of shaft770. Specifically, receptacle782has opening785, annular cantilever beams783with split gaps787and ribs789at their distal ends. When brush unit716is mounted on dispensing platform732as shown inFIG. 9e, pushbutton posts are inserted into receptacles782,786by deflecting cantilever beams to expose the heads802,806of pushbutton posts754,758through openings781,785such that the ribs spring back to latch on retention neck755,757of pushbutton posts754,758. In practice, the length of the cantilever beams may be shortened and the protrusion of the retention ribs may be minimized for providing effective interference for the insertion of the pushbutton posts to ensure locking of each pushbutton on the receptacle when fully engaged. The protrusion of each pushbutton head from the outer surface of the dispensing platform wall exceeds the thickness of the ribs of the receptacle such that full depression of the pushbutton head onto the receptacle opening can deflect the ribs away from the path of the detention neck to allow detachment of the brush unit from the dispensing platform. To detach the brush unit from the dispensing platform, both heads of the pushbutton posts can be pressed out of the receptacles by the thumb of one hand. The features of the receptacle configuration can be molded onto the support wall of the dispensing platform by injection molding. Similarly, the features of the pushbutton posts can be molded onto the support bracket of the brush unit by injection molding techniques. Although the above fastening features are illustrated on a dentifrice dispensing electrical toothbrush, the same fastening features are applicable to a brush unit of an electrical toothbrush. In application to an electrical toothbrush, a detachable brush unit can be molded with pushbutton posts and heads to mate with the receptacles on the shaft channel wall which are extended from the handle of the electrical toothbrush.

The invention has been described in detail with reference to preferred embodiments thereof. However, it is understood that variations and modifications can be effected within the spirit and scope of the invention.