Drivetrain assembly and systems and methods for generating sweeping and tapping motions in oral cleaning devices with periodic brush-head tapping transient

Abstract

A method and drivetrain assembly for cleaning teeth using an oral cleaning device are disclosed. The method involves driving first and second coils (wound around arms of a U-shaped structure) with signals to generate opposing or same polarities at the distal ends of the structure, thereby rotating or displacing a magnet. The magnet's motion is transmitted to a brush head member, enabling rotational movement about a central axis or transient movement along another axis. The transient movement pattern is characterized by heightened amplitude. The drivetrain assembly includes a resonator, magnet, coupling spring, U-shaped structure with coils, and a controller configured to generate driving signals for rotational and transient movement patterns. The controller phase-shifts signals to switch between movement patterns. This approach enhances oral cleaning efficiency by providing dynamic brush head motion patterns.

Description

2025PF00380DRIVETRAIN ASSEMBLY AND SYSTEMS AND METHODS FOR GENERATING SWEEPING AND TAPPING MOTIONS IN ORAL CLEANING DEVICES WITH PERIODIC BRUSH-HEAD TAPPING TRANSIENTField of the Disclosure

[0001] The present disclosure relates generally to personal care devices, such as power toothbrush devices, and more specifically to drivetrain assemblies for power toothbrushes, and more particularly to systems and methods for improving cleaning performance by generating sweeping and tapping motions with a single actuator and phase shifting the driving signals to induce a transient effect.Background

[0002] Current modern power toothbrush devices use rotary motion about a central axis of the brush head. This motion is known as a sweeping motion. A simplified schematic representation of a modern power toothbrush is shown in FIG. 1. As shown in FIG. 1, power toothbrush 10 has a handle 12 and a brush head 14. Bristles 16 are shown extending from brush head 14. In use, brush head 14 is driven by a drive system contained within handle 12. The bristles are typically rotated by the drive system about central axis A in a sweeping motion SM. The sweeping motion is typically embodied as movement that is linear, rotational, or a combination of both linear and rotational and the movement is tangential to the direction that the bristles are facing.

[0003] Unfortunately, toothbrush devices that employ the sweeping motion alone are not optimized for all target areas in the mouth (e.g., interproximal areas, gumline areas, incisor surfaces, molar surfaces, and overall surface areas of the teeth). Achieving proper cleaning performance at all target areas depends on a number of factors, including toothbrush layout, motion of the toothbrush, and user handling. Although manufacturers can control toothbrush layout or design, it is challenging to design a toothbrush that performs optimally at all target areas due to conflicting requirements for the different areas. Consequently, toothbrushes can have non-optimal performance at certain areas of interest. Although consumers could ideally use different types of toothbrushes to achieve the best cleaning in all the target areas, consumers only employ a single toothbrush device for daily oral care routines.2025PF00380

[0004] While conventional systems and methods rely on continuous periodic driving signals to generate brush head motion, such systems and methods are limited in the size of the angular motion of the brush head.

[0005] Thus, there is a need in the art for improved power toothbrush devices and systems and methods that achieve stain and / or plaque removal and gum health objectives using simultaneous actuation of the sweeping and tapping motions with a single actuator and phase shifting the driving signals to achieve temporary, heightened motion in multiple degrees of freedom.Summary of the Disclosure

[0006] The present disclosure is directed generally to inventive electric or powered personal care devices, such as, an electric toothbrush or shaver, and methods for producing high performance cleansing results using the electric or powered personal care devices. The inventive systems achieve improved stain and / or plaque removal and gum health objectives by precisely and controllably generating a power tapping motion in combination with a sweeping motion with a single actuator and phase shifting the driving signals to achieve temporary, heightened motion in multiple degrees of freedom. The aforementioned limitations can be overcome by combining the sweeping motion with a vertical up and down periodic motion that can be generated and driven with a suitable drivetrain and phase shifting the driving signals to induce a transient effect. While two separate mechanical systems can be coupled together to drive the tapping and sweeping motions, such a combination comes with drawbacks of cost, size, and complexity that prohibit competitiveness in the power toothbrush market. Various embodiments and implementations herein are directed to improved systems having a brush head member, a set of bristles, and a drivetrain assembly that achieves both the sweeping and tapping motions without compromising on other qualities, such as, cost, size, or user experience. The drivetrain assembly allows freedom of rotation about the central axis and motion in the vertical direction parallel to the direction of the bristles or an axis of alignment of the bristles and also drives these motions. Thus, the improved drivetrain assembly simultaneously generates (i) periodic movement about a central axis of the device or along a line that is tangential to the brush head member; and (ii) periodic linear movement in a direction that is parallel to a z-axis of the device or an axis of alignment of the bristles. Applicant has recognized and appreciated that electric or powered personal care devices2025PF00380can be significantly improved upon by controllably moving the bristles in a sweeping motion and controllably driving the bristles in a direction that is parallel to the z-axis of the device or an axis of alignment of the bristles (i.e., in a tapping motion), where the movement is within a particular range of critical amplitudes and frequencies. Additionally, Applicant has recognized and appreciated that intentionally intermittently phase shifting the driving signals for a defined, brief duration significantly improves the dislodgement of debris and plaque, particularly in hard-to-reach areas, thereby advancing the efficacy of oral cleaning devices beyond the capabilities of systems and methods that rely on continuous periodic driving signals.

[0007] In a first aspect, a method for cleaning teeth using an oral care device is provided. The method comprises the steps of: 1) driving with first and second driving signals first and second coils that are wound around first and second arms of a U-shaped core, respectively, to generate an opposing polarity at distal ends of the first and second arms; 2) rotating a magnet with a torque created by the opposing polarity of the U-shaped core; 3) transmitting the rotation of the magnet to a brush head member of the oral cleaning device such that the brush head member rotates about a central axis of the oral cleaning device for a predetermined time interval in a rotational movement pattern; 4) after the predetermined time interval, phase-shifting a driving signal to the first or the second coil to generate a same polarity at the distal ends of the first and second arms of the U-shaped core; 5) displacing the magnet with a force created by the same polarity of the U-shaped core; and 6) transmitting the displacement of the magnet to the brush head member of the oral cleaning device such that the brush head member moves along another axis of the oral cleaning device in a transient movement pattern.

[0008] According to an embodiment, the method further comprises the step of phase-shifting the driving signal to the first or the second coil such that the phase-shifted driving signal interacts with first and second poles of the magnet to generate the rotational movement pattern again.

[0009] According to an embodiment, the phase-shift of the phase-shifted driving signal is 180 degrees to switch from the rotational movement pattern to the transient movement pattern.

[0010] According to an embodiment, the transient movement pattern is characterized by a heightened amplitude that is higher than a later stabilized amplitude, and wherein the heightened amplitude is larger than any amplitude exhibited by the brush head member as it rotates about the central axis in the rotational movement pattern.2025PF00380

[0011] According to an embodiment, the another axis is substantially parallel to an axis of alignment of bristles of the brush head member.

[0012] According to an embodiment, each of the first and second driving signals comprises a time-varying voltage signal comprising a cyclical waveform and the predetermined time interval is a full cycle of the cyclical waveform.

[0013] In a second aspect, a drivetrain assembly of an oral cleaning device is provided. The drivetrain assembly comprises a resonator configured to transmit motion to a brush head member, wherein the resonator is configured to rotate about a central axis of the oral cleaning device in a rotational movement pattern, and wherein the resonator is configured to move along another axis of the oral cleaning device in a transient movement pattern. A magnet is also included that is connected to the resonator, as well as a coupling spring connected to the magnet and a brush head shaft that transmits generated motion to the brush head member. A U-shaped core having a first arm with a first coil and a second arm with a second coil and a controller are also included. The controller is configured to generate and transmit first and second driving signals to the first and second coils wound around the first and second arms of the U-shaped core, respectively, wherein the first and second driving signals interact with first and second poles of the magnet, respectively, to generate the rotational movement pattern, and, after a predetermined time interval, phase-shift a driving signal to the first or the second coil, wherein the phase-shifted driving signal interacts with the first and second poles of the magnet to generate the transient movement pattern.

[0014] According to an embodiment, the controller is further configured to phase-shift the driving signal to the first or the second coil, wherein the phase-shifted driving signal interacts with the first and second poles of the magnet to generate the rotational movement pattern again.

[0015] According to an embodiment, the phase-shift of the phase-shifted driving signal is 180 degrees to switch from the rotational movement pattern to the transient movement pattern.

[0016] According to an embodiment, wherein the transient movement pattern is characterized by a heightened amplitude that is higher than a later stabilized amplitude.

[0017] According to an embodiment, wherein the heightened amplitude is larger than any amplitude exhibited by the brush head member as it rotates about the central axis in the rotational movement pattern.2025PF00380

[0018] According to an embodiment, the another axis is substantially parallel to an axis of alignment of bristles of the brush head member.

[0019] According to an embodiment, each of the first and second driving signals comprises a time-varying voltage signal comprising a cyclical waveform.

[0020] According to an embodiment, the predetermined time interval is a full cycle of the cyclical waveform.

[0021] According to an embodiment, the first and second driving signals interact with the first and second poles of the magnet by generating an opposing polarity at distal ends of the first and second arms and the phase-shifted driving signal interacts with the first and second poles of the magnet by generating a same polarity at the distal ends of the first and second arms.

[0022] In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as “memory,” e.g., volatile, and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects as discussed herein. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers.

[0023] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.2025PF00380

[0024] These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.Brief Description of the Drawings

[0025] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments.

[0026] FIG. 1 is a simplified schematic representation of an end view of a modern power toothbrush device configured to employ a sweeping motion, according to aspects of the present disclosure.

[0027] FIG. 2 is a simplified schematic representation of a portion of a power toothbrush device, according to aspects of the present disclosure.

[0028] FIG. 3 is a simplified schematic representation of an end view of a power toothbrush device configured to employ sweeping and tapping motions, according to aspects of the present disclosure.

[0029] FIG. 4 is a schematic representation of a power toothbrush device, according to aspects of the present disclosure.

[0030] FIG. 5 is another schematic representation of a power toothbrush device, according to aspects of the present disclosure.

[0031] FIG. 6A is a schematic representation of a portion of a drivetrain assembly of a power toothbrush device, according to aspects of the present disclosure.

[0032] FIG. 6B is a schematic representation of a portion of a drivetrain assembly of a power toothbrush device, according to aspects of the present disclosure.

[0033] FIG. 6C is a schematic representation of the brush head driving actuator performing a sweeping motion, according to aspects of the present disclosure.

[0034] FIG. 6D is a schematic representation of the brush head driving actuator performing a tapping motion, according to aspects of the present disclosure.2025PF00380

[0035] FIG. 7A depicts an exemplary schematic representation of the coils wrapped around the arms of the U-shaped core of the drivetrain assembly, according to aspects of the present disclosure.

[0036] FIG. 7B is a schematic representation of example driving voltages applied by individual electronic drivers to the coils of FIG. 7A, according to aspects of the present disclosure.

[0037] FIG. 8 is a diagrammatic representation of example driving voltages applied to each coil at distinct frequencies for generating the sweeping and tapping motions simultaneously, according to aspects of the present disclosure.

[0038] FIG. 9 is a schematic representation of an example dual arbitrary waveform generator driving two coils of the drivetrain assembly, according to aspects of the present disclosure.

[0039] FIG. 10 is a schematic representation of an example coil driving circuit for generating sweeping and tapping motions in a drivetrain assembly, according to an alternative embodiment of the present disclosure.

[0040] FIG. 11 is a waveform diagram illustrating coil voltages during transitions between sweeping and tapping motions, according to aspects of the present disclosure.

[0041] FIG. 12 is a flowchart depicting a method of driving a drivetrain of an oral cleaning device to achieve rotational and transient movement patterns, according to aspects of the present disclosure.Detailed Description of Embodiments

[0042] The present disclosure describes various embodiments of improved systems and methods for driving brush heads of electric or powered personal care devices, such as electric toothbrushes or shavers and the like. Applicant has recognized and appreciated that personal care devices can provide improved cleansing performance at critical areas of the user’s mouth by driving the bristles of the toothbrush in a vertical motion that is parallel to the direction of the bristles, in addition to movement about a central axis of the device or along a line that is tangential to the brush head member. As used herein, the term “vertical” does not mean an absolute direction with respect to the ground but instead is used to indicate a relative direction of movement illustrated in the Figures. As described herein, the inventive tapping motion within power toothbrush devices: (i) achieves deeper reach in gum pockets to remove subgingival plaque, (ii)2025PF00380achieves higher peak forces at surfaces which improve plaque and / or stain removal, (iii) prevents pinning of bristle tufts which improves plaque removal by restoring beneficial tuft sweeping behavior, (iv) achieves more resilience to variables of use like toothbrush placement, toothbrush angle, and toothbrush pressure, and (v) provides new options for experiential modes for the consumer. Additionally, improved cleansing performance can be realized by varying the movement of the bristles about the central axis of the device or along a line that is tangential to the brush head member. Accordingly, exemplary improved systems and methods described or otherwise envisioned herein provide a brush head member having a set of bristles and a drivetrain assembly to generate rotational and linear movements alone or simultaneously using a single actuator and intentionally phase shifting the driving signals for a defined duration to vary the movements. The periodic linear movement is transmitted by a brush head shaft to move the bristles in a direction that is parallel to the z-axis of the device. Applicant has recognized and appreciated that such controlled linear movement can be combined with rotational movement to provide improved cleaning performance. Additionally, the intentional phase shifting of one or more driving signals provides a transient effect characterized by heightened amplitudes in the multiple degrees of freedom to further improve cleaning performance.

[0043] A particular goal of utilization of the embodiments and implementations herein is to provide a mechanism to provide a combined sweeping and tapping motion in a power toothbrush device like, e.g., a Philips Sonicare™ electric toothbrush (manufactured by Koninklijke Philips N.V.). However, the components of the device may be utilized with many other personal care devices, including oral care devices, oral cleaning devices, flossers, skin cleaners, and many other devices. This disclosure should not be limited by the specific embodiments depicted and described.

[0044] Power toothbrushes (PTBs) are electrically driven toothbrushes. The drivetrain in power toothbrushes often includes a double-resonant mechanism consisting of two moving bodies and their connected springs to help the generated motion such that less power is required and to minimize vibrations of the product. The double-resonant mechanism is driven via two coils having a U-shape metal core. When electrical signals pass through the coils, a magnetic field is generated that either attracts or repels a permanent magnet creating a torque to make the permanent magnet rotate. When one coil attracts the magnet, and the other coil repels the magnet, a rotational motion is generated. When both coils either attract or repel, the magnet makes a vertical translational motion.2025PF00380

[0045] FIG. 2 shows a simplified schematic representation of a portion of a power toothbrush device 100 configured to generate a sweeping motion and / or a tapping motion. Power toothbrush device 100 includes brush head 114 and bristles 116 which can be driven to rotate about central axis A and pulse or tap in direction RD2. The directions provided in FIG. 2 are included to demonstrate the spatial terminology used in the art and the present application. As used herein, the term “vertical” means the direction indicated. Axial direction AD is parallel to central axis A and extends along a y-axis of the device 100. Radial direction RD 1 is orthogonal to central axis A and radial direction RD2 and extends along an x-axis of the device 100. Radial direction RD2 is orthogonal to both axial direction AD and radial direction RD1, parallel to the axes of the bristles 116 depicted, and extends along a z-axis of the device 100. The tapping motion described herein refers to controllable movement of the brush head and / or bristles in radial direction RD2. In other words, the tapping motion refers to motion of the bristles that is parallel to an axis of alignment of the bristles or normal (i.e., perpendicular) to the brush head member. The sweeping motion refers to rotary and / or linear motion of the bristles that is perpendicular to the axis of alignment of the bristles. In embodiments, the tapping motion refers to controllable movement of the brush head and / or bristles in radial direction RD2 by rotating the brush head shaft about an axis extending in radial direction RD1 (i.e., about an x-axis of the device).

[0046] Referring to FIG. 3, a schematic representation of an end view of power toothbrush device 100 is provided. Device 100 is configured to generate a variety of motions, each motion comprising a summation (i.e., a cumulative act, motion, or effect) of sweeps or strokes and pulses or taps. The sweeps or strokes are directed in direction SM, (which would be in a direction between occlusal surfaces (i.e., biting surfaces) and the gumline when the toothbrush is held with the bristle tips pointing toward a buccal side of the teeth). The pulses or taps are directed in the vertical direction TM (which would be a lingual to facial direction when the toothbrush is held with the bristle tips pointing toward a buccal side of the teeth). As discussed in greater detail herein, the power toothbrush device 100 can be configured to turn on and off the sweeping and tapping motions (SM and TM) for optimizing motion to a specific region that a particular motion is most beneficial for. In some cases, the particular motion comprises either the sweeping motion alone or the tapping motion alone. In other cases, the particular motion comprises some combination of the sweeping motion and the tapping motion. For example, in embodiments, the tapping motion alone can be used for the lower lingual anterior region of the mouth or to better reach at interproximal2025PF00380regions in-between teeth. The tapping motion can be used with the sweeping motion for the buccal anterior region of the mouth. Alternatively, the sweeping motion alone can be used for the buccal anterior region of the mouth.

[0047] The tapping motion improves the performance of the sweeping motion, in part, by untrapping or unpinning the bristle tufts. Bristle trapping or pinning is a phenomena where, under heavy loads, the bristles can become constrained or trapped such that they no longer freely move according to the sweeping motion delivered by the drivetrain. When the user applies too much load when brushing, the bristle tufts can become partially constrained in their movement on the surface of the teeth. As a result of the constraint, the sweeping motion is reduced, and the cleaning performance can suffer. When the user applies even more load, the bristle tufts can become trapped or pinned where the tufts do not move at all when brushing. As a result of the trapped or pinned bristles, there is no sweeping motion, and the user derives no benefit from the sweeping motion from the drivetrain assembly. When bristles are constrained or trapped, the cleaning benefits only resume when the user manually moves the product to a new orientation and frees the bristles from the heavy loads.

[0048] The sweeping motion performs best when the bristles touch the surface of the tooth and can move freely along large surface areas without being constrained. When brushing with sweeping and tapping motions together, the bristle tufts splay out as the load increases or as the brush head moves in direction DR1 due to the drivetrain assembly generating the vertical up-down movement (i.e., the tapping motion). As the load increases due to the force exerted from the drivetrain assembly or otherwise due to user applied load for example, the tufts can become more and more constrained. However, if the amplitude of the brush head movement in direction DR1 is large enough, the large amplitude movement can cause buckling of a constrained or trapped bristle and effectively release or unload the bristle. Thus, the addition of the tapping motion to the sweeping motion allows the bristles to move with more freedom, thereby improving cleaning performance.

[0049] Critically, when the brush head moves in direction DR2 during the tapping motion, the behavior reverses and as the load decreases further, the tufts become less and less constrained. The tapping motion can allow the tufts to cover a larger surface area during the sweeping motion and improves plaque removal by restoring the beneficial sweeping motion.2025PF00380

[0050] The addition of the tapping motion to the sweeping motion also achieves a deeper reach into gum pockets to remove subgingival plaque. Within gum pockets, the addition of the tapping motion achieves improved cleaning performance on marginal areas, interproximal areas, mesial areas, and buccal areas, and an improved overall cleaning performance. In example embodiments, the deeper reach and improved cleaning performance is achieved under a 30 degree roll angle, a 45 degree roll angle, or a 60 degree roll angle, or any suitable roll angle. Thus, the addition of the tapping motion renders the cleaning efficiency of the brush to be more robust to user orientation, and less dependent on the user’s technique, than using the sweeping motion alone.

[0051] The improved cleaning performance can be achieved by using critical operating parameters for the tapping motion discussed herein. While a variety of drivetrain assemblies can be implemented to generate the tapping motion, we will discuss several exemplary assemblies below to illustrate how the invention can be implemented and practiced.

[0052] Referring to FIG. 4, a schematic representation of the power toothbrush device 100 is shown. A head member 104, brush head 114, and / or bristle face 115 are mounted so as to be able to move relative to the body portion housing 102. The movement can be any of a variety of different movements, including vibrations or rotation, among others. According to one embodiment, head member 104 is mounted to the body portion housing 102 so as to be able to vibrate relative to body portion housing 102, or, as another example, brush head 114 is mounted to head member 104 so as to be able to vibrate relative to body portion housing 102, or, as another example, bristle face 115 is mounted to head member 104 so as to be able to vibrate relative to body portion housing 102. The head member 104 can be fixedly mounted onto body portion housing 102, or it may alternatively be detachably mounted so that head member 104 can be replaced with a new one when the bristles or another component of the device are worn out and require replacement.

[0053] Referring to FIG. 5, the body portion 102 can include a drivetrain assembly 122 with an actuator or motor for generating movement and a resonator 120 configured to transmit the generated movements to head member 104. For example, drivetrain assembly 122 comprises a motor or electromagnet(s) that generates movement of brush head shaft 124, which is subsequently transmitted to the head member 104. Drivetrain assembly 122 can include components such as a power supply, an oscillator, and one or more electromagnets, among other components. In this2025PF00380embodiment the power supply comprises one or more rechargeable batteries 126 (see FIG. 4) which can, for example, be electrically charged in a charging holder in which power toothbrush device 100 is placed when not in use (not shown).

[0054] Still referring to FIG. 5, the body portion 102 of the device 100 also comprises a controller 130. Controller 130 may be formed of one or multiple modules and is configured to operate the power toothbrush device 100 in response to an input, such as input obtained via user input or an input from a sensor within the device. Controller 130 can comprise, for example, a processor 132 and a memory 134, and can optionally include a connectivity module 138. The processor 132 may take any suitable form, including but not limited to a microcontroller, multiple microcontrollers, circuitry, a single processor, or plural processors. The memory 134 can take any suitable form, including a non-volatile memory and / or RAM. The non-volatile memory may include read only memory (ROM), a hard disk drive (HDD), or a solid state drive (SSD). The memory can store, among other things, an operating system. The RAM is used by the processor for the temporary storage of data. According to an embodiment, an operating system may contain code which, when executed by controller 130, controls operation of the hardware components of power toothbrush device 100. According to an embodiment, connectivity module 138 transmits collected sensor data, and can be any module, device, or means capable of transmitting a wired or wireless signal, including but not limited to a Wi-Fi, Bluetooth, near field communication, and / or cellular module.

[0055] Referring to FIGS. 6A-6B, a close-up view of the resonator 120 and a perspective view of the drivetrain assembly 122 within the handle 112 are shown, respectively. FIG. 6C depicts a top view of an actuator 200 and magnet 202 of the drivetrain assembly 122 along with a crosssection and working principle view of the magnet 202 performing the sweeping motion. FIG. 6D depicts that of the magnet 202 performing the tapping motion, described below. The actuator 200 includes a core 204 and first and second coils 206 and 208, respectively, coupled to the core 204. In this example, the core 204 is a metal U-shaped core and has first arm 210 and second arm 212 which the first and second coils 206 and 208 are wrapped around, respectively. As explained further below, the winding direction of the coils around the core 204 influences the motion made during the phase shifts generated by the coils. In this example, the coils 206 / 208 are wrapped around the respective arms 210 / 212 in opposite winding directions, but it is contemplated that the coils can be wrapped in like winding directions.2025PF00380

[0056] As shown in FIG. 6C, a magnet 202, such as a permanent magnet, is positioned adjacent to the distal ends of the arms 210 / 212 of the core 204 and has a north pole and south pole. The magnet 202 is connected to the brush head shaft 124 via a coupling spring 214 which then transmits the motion of the magnet 202 to the brush head shaft 124. In some embodiments, the drivetrain assembly 122 includes a double resonant mechanism that is driven by the first and second coils 206 / 208. The first and second coils 206 / 208 are driven in parallel by the controller 130 with an alternating voltage (as should be understood by a person of ordinary skill in the art in conjunction with a review of this disclosure). The alternating voltage creates an alternating north and south pole at the distal end of the U-shaped core 204 (i.e., alternating between a north pole at the distal end of the first arm 210 / a south pole at the distal end of the second arm 212 and a south pole at the distal end of the first arm 210 / a north pole at the distal end of the second arm 212). The north and south poles created at the core 204 interact with the north and south poles of the magnet 202, causing the like poles to repel each other and the opposing poles to attract each other. The switching of the attraction and repulsion of the magnet 202 to the core 204 provides an oscillatory rotational motion to the resonator 120 which is transmitted to the brush head shaft 124 via the coupling spring 214 and allows the brush head 114 and cleaning elements (i.e., bristles 116) to perform a first movement pattern (i.e., the sweeping motion). In this embodiment, the coupling spring 214 extends between the first and second arms, as shown in FIG. 6A.

[0057] As described above, cleaning performance can be enhanced by adding an additional degree of freedom to the brush head motion, such as tapping. As described above, the sweeping motion is created by the controller 130 generating and transmitting a voltage to the coils 206 / 208 such that the coils 206 / 208 have an alternating opposing polarity. The coils 206 / 208 can also be driven in a way that they both have the same or a like polarity, alternating between north and south poles at a specified frequency. Referring to FIG. 6D, to induce the tapping motion, the coils 206 / 208 can have the same polarity, alternating between both arms 210 / 212 having a north pole and then a south pole, which interacts with the magnet 202, causing the magnet to be pulled or pushed vertically with respect to the core 204, allowing the brush head 114 and cleaning elements to perform a second movement pattern (i.e., the tapping motion). As described further below, by driving the coils in a certain way, the sweeping and tapping motion of the brush head 114 can happen alone or simultaneously, advantageously providing motion with two degrees of freedom without the need of a second actuator.2025PF00380

[0058] Referring to FIGS. 7A-7B, in the described actuator system, each of the two coils 206 / 208 is driven independently by separate electronic drivers. This configuration enables the introduction of a controllable phase shift between the signals supplied to each coil 206 / 208. The resulting phase shift directly influences the magnetic field generated by the coils, thereby affecting the actuator’s motion characteristics. In this example, when a phase shift of 180° is applied between the coil signals, the actuator exhibits the tapping motion. Conversely, when a phase shift of 0° is applied between the coil signals, the actuator exhibits the sweeping motion, which is equivalent to the behavior observed when both coils are connected together and driven in unison. It should be understood that the specific motion modes associated with the 0° and 180° phase shifts are dependent on the winding direction of the coils and their connection to the electronic drivers. Altering the winding direction and / or the driver connections can reverse the motion modes. In the current embodiment and as illustrated in FIG. 7A, the coils are configured with opposite winding directions, as explained above.

[0059] To create the combined, simultaneous motion of sweeping and tapping, the 0° phase shifted voltage is combined with the 180° phase shifted voltage, with the 0° phase shifted voltage having a different frequency than the 180° phase shifted voltage. If the frequencies are the same, the voltages for one coil will cancel out the other. An exemplary table detailing the logic for the combination of driving signals with the two frequencies based on embodiments is shown in Table 1 below.Table 1: Combination of Sweeping Driving Voltage with Tapping Driving Voltage

[0060] Referring now to FIGS. 8-9, in this example, the controller is configured to drive each coil independently, allowing for precise control over the magnetic field dynamics by generating distinct driving signals for each coil, as exemplified in Table 1. Referring to FIG. 9, the driving2025PF00380mechanism can be implemented using a dual arbitrary waveform generator. The generator produces synchronized signals to the first and second coils 206 / 208, as shown in FIG 7B. The synchronization of the signals allows for the maintained coordinated control over the actuator’s motion. The generated signals are then amplified and transmitted to the respective coils.

[0061] In accordance with an alternative embodiment, instead of using analog amplifiers as shown in FIG. 9, a full bridge for each coil can be used, as shown in FIG. 10. In this configuration, a control unit 1000 can generate digital signals corresponding to the desired driving voltage profiles shown in FIG. 8 and Table 1. The electronic drivers act as an interface between the control unit and the switches Sil, S12, S13, S14, S21, S22, S23, and S24. In accordance with an embodiment, the switches are implemented using MOSFETs. To operate both high-side and low-side switches effectively, electronics may be needed to generate appropriate gate-source voltages to ensure reliable switching performance and accurate signal delivery to each coil.

[0062] The operational effect of the power toothbrush device described herein is that it can provide improved cleansing performance at critical areas of the mouth by driving the bristles of the toothbrush in a vertical periodic motion that is parallel to the direction of the bristles or an axis of alignment of the bristles. The tapping motion: (i) achieves deeper reach in gum pockets to remove subgingival plaque, (ii) achieves higher peak forces at surfaces which improve plaque and / or stain removal, (iii) prevents pinning of bristle tufts which improves plaque removal by restoring beneficial tuft sweeping behavior, (iv) achieves more resilience to variables of use like toothbrush placement, toothbrush angle, and toothbrush pressure, and (v) provides new options for experiential modes for the consumer.

[0063] In some embodiments, an alternative variation approach is employed that exploits a transient effect on the dynamic behavior of the system as demonstrated by FIGS. 11 and 12. The transient effect, as described in the present disclosure, refers to a temporary dynamic response exhibited by the drivetrain assembly of the oral cleaning device by altering the driving signals applied to the actuator. Specifically, this effect is achieved by introducing a phase shift, such as 180 degrees, between the driving signals of the first and second coils of the U-shaped structural component after the sweeping motion described above has occurred for a predetermined time period. This phase shift generates a same polarity at the distal ends of the arms of the structural component, resulting in a unidirectional force that displaces the magnet connected to the brush2025PF00380head in the tapping motion described above. The phase shift causes the drivetrain to experience a transient effect or state that is characterized by an initial heightened amplitude of motion, which is greater than the amplitude observed during the steady-state rotational movement of the brush head. This heightened amplitude gradually stabilizes over a short duration, providing a vertical displacement or tapping motion that complements the rotational sweeping motion. The transient effect enhances the cleaning efficacy of the device by introducing motion in an additional degree of freedom, thereby improving the removal of debris and plaque from the teeth.

[0064] FIG. 11 shows a waveform diagram illustrating the actuation principle and example driving voltages applied to the coils during transitions between sweeping rotational motion and tapping translational motion in the drivetrain assembly of the oral cleaning device. The figure highlights the dynamic behavior of the actuator system as the actuator alternates between differential-mode rotation and tapping motion, each driven by distinct voltage signals applied to the coils.

[0065] The diagram in FIG. 11 includes three distinct operational states: the sweeping motion SM, the tapping motion TM, and the subsequent return to the sweeping motion SM. In the sweeping motion state, the voltages applied to the coils are phase-shifted by 0°, creating opposing polarities at the distal ends of the U-shaped magnetic structure. This differential polarity generates a torque that rotates the magnet, resulting in the rotational movement of the brush head about the central axis. The forces F ft and Fright depicted in the figure represent the magnetic interactions that drive the rotational motion.

[0066] During the transition to the tapping motion TM, the controller introduces a temporary phase shift of 180° between the driving signals applied to Coill and Coil2 to induce transient behavior. This phase shift causes both coils to generate the same polarity at the distal ends of the U-shaped structure, producing a unidirectional force that displaces the magnet vertically. The tapping motion TM is characterized by linear movement along an axis parallel to the alignment of the bristles, enhancing cleaning performance by introducing motion in an additional degree of freedom. The forces F ft and Frigtax aligned in the same direction during this state, as shown in the figure.

[0067] After a short and specified time, the controller switches back to the sweeping motion SM by restoring the 0° phase shift between the coil voltages. This transition re-establishes the2025PF00380differential polarity at the distal ends of the U-shaped magnetic structure, resuming the rotational movement of the brush head. In this example, this transient effect is created only for a short time to introduce a vertical displacement component to the movement of the brush head and take advantage of the transient behavior. The waveform diagram illustrates the periodic nature of the voltage signals applied to the coils, with the transitions between the sweeping motion SM and tapping motion TM clearly marked.

[0068] The transient behavior observed during the tapping motion TM is characterized by an initial heightened amplitude of motion, which gradually stabilizes over time. This transient effect enhances the cleaning efficacy of the device by providing a temporary increase in the displacement of the brush head, allowing for improved removal of debris and plaque from hard-to-reach areas.

[0069] FIG. 11 also demonstrates the synchronization of the coil voltages, which is necessary for maintaining coordinated control over the motion of the actuator. The waveform profiles for Coill and Coil2 are depicted as square waves with flat intervals, enabling accurate control over the timing and amplitude of the transitions between motion states. This configuration allows the drivetrain assembly to perform simultaneous sweeping motion and tapping motion or alternate between them as required, without relying on additional actuators.

[0070] While the ideal moment of transient is described as being at the end of a full cycle (e.g., approximately 4 ms per cycle in this example) so as not to interrupt the sweeping mid cycle, it should be understood that it can occur at other moments as well if desired. The predetermined time interval may also vary depending on the frequency of the waveform, allowing for adaptability to different operational speeds of the oral cleaning device 100. Furthermore, the controller 130 may be configured to dynamically adjust the predetermined time interval based on real-time feedback from sensors monitoring the motion of the brush head 114, ensuring optimal transient effects for enhanced cleaning efficacy. These embodiments demonstrate the versatility of the drivetrain assembly 122 in accommodating various waveform types and operational conditions while maintaining the fundamental functionality defined herein.

[0071] The controller maintains the phase shifted driving signals for a short and specific duration that is sufficient to induce a transient effect in the drivetrain assembly. This short and specific duration is intentionally brief, for example, for a time period that is sufficient to allow at2025PF00380least one full cycle of the tapping motion TM, ensuring the interruption in the sweeping motion is minimal and preserves overall device performance.

[0072] In one embodiment, the time-varying voltage signals driving the coils may be a sinusoidal waveform, ensuring smooth transitions between the rotational and transient movement patterns. In another embodiment, the cyclical waveform may be a square wave with flat intervals, allowing for precise control over the timing and amplitude of the transient movement. Alternatively, the waveform could be triangular or sawtooth, providing a gradual ramp-up or rampdown in voltage to optimize the transient behavior. The cyclical waveform may also be modulated in amplitude or frequency to achieve specific cleaning effects. In yet another embodiment, the waveform could be digitally synthesized to include custom patterns, such as a combination of sinusoidal and square waveforms, to optimize the transient behavior. The waveform's frequency could vary across a wide range, for example, from about 50 Hz to about 300 Hz, depending on the desired cleaning intensity and user preference, with about 260 Hz being a preferred voltage for sweeping in some embodiments. Additionally, the waveform may be generated using different electronic components, such as a microcontroller or a dedicated signal generator circuit, to ensure compatibility with various drivetrain designs. These variations in the first driving signal allow for adaptability in the drivetrain assembly while maintaining the fundamental functionality of inducing transient motion in the brush head member.

[0073] The predetermined time interval for the cyclical waveform may vary depending on the cleaning mode, such as a shorter interval for quick bursts of tapping motion or a longer interval for sustained rotational movement. Additionally, the amplitude of the voltage signal may be adjustable, enabling customization of the brush head's motion intensity to suit different cleaning needs or user preferences. In yet another embodiment, the controller may dynamically adapt the waveform's frequency based on real-time feedback from sensors monitoring the brush head's motion, ensuring optimal performance across varying oral conditions.

[0074] FIG. 12 depicts a flowchart illustrating a method 1200 for driving a drivetrain of an oral cleaning device to achieve rotational and transient movement patterns according to an exemplary embodiment. The method utilizes the specific arrangement of the drivetrain assembly, including U-shaped core 204, coils 206 and 208, and magnet 202, to generate distinct motion patterns for improved cleaning performance. This flowchart highlights the sequential steps involved in2025PF00380transitioning between rotational and transient movement patterns, demonstrating the versatility and precision of the drivetrain assembly 122 in achieving enhanced oral cleaning performance.

[0075] The method begins at step 1210, where first and second coils that are wound around first and second arms of a U-shaped core, respectively, are driven with first and second driving signals. The driving signals applied to the coils generate an opposing polarity at distal ends of the first and second arms of the U-shaped core. This opposing polarity creates a magnetic interaction that facilitates the rotational movement of the drivetrain assembly 122.

[0076] Next, at step 1220, the opposing polarity at the distal ends of the U-shaped core 204 generates a torque that rotates magnet 202 positioned adjacent to the core. The magnet, which is connected to the brush head shaft, is driven into oscillatory rotational motion by the alternating magnetic forces created by the coils 206 and 208.

[0077] At step 1230, the rotational motion of the magnet 202 is transmitted to a brush head 114 of the oral cleaning device. This transmission enables the brush head 114 to rotate about a central axis of the oral cleaning device, creating a sweeping motion SM. The sweeping motion SM is maintained for a predetermined time interval, during which the bristles 116 of the brush head perform a rotational movement pattern to clean teeth.

[0078] After the predetermined time interval, at step 1240 of the method, a phase shifted driving signal is applied to one of the coils 206 or 208. Specifically, the driving signals are phase shifted to generate a same polarity at the distal ends of the first and second arms of the U-shaped core 204. This phase shift alters the magnetic interaction, transitioning the drivetrain assembly 122 from rotational motion to a transient state.

[0079] Next, at step 1250, the same polarity at the distal ends of the U-shaped core 204 creates a unidirectional force that displaces magnet 202 vertically. This displacement introduces a transient tapping motion TM, which is characterized by a linear movement along an axis parallel to the alignment of the bristles 116.

[0080] Finally, at step 1260, the vertical displacement of the magnet 202 is transmitted to the brush head 114 of the oral cleaning device. This transmission causes the brush head 114 to move along another axis of the oral cleaning device, resulting in a transient movement pattern TM. The transient movement, which complements the rotational sweeping motion SM, enhances the2025PF00380cleaning efficacy by introducing motion in an additional degree of freedom. This transient effect is particularly effective dislodging debris and plaque from hard-to-reach areas, such as interproximal spaces and gum pockets.

[0081] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0082] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0083] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified.

[0084] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

[0085] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list2025PF00380of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

[0086] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0087] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0088] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the inventive teachings is / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

Claims

2025PF00380ClaimsWhat is claimed is:

1. A method for cleaning teeth using an oral cleaning device (100), the method comprising:driving with first and second driving signals first (206) and second (208) coils that are wound around first (210) and second (212) arms of a U-shaped core (204), respectively, to generate an opposing polarity at distal ends of the first (210) and second (212) arms;rotating a magnet (202) with a torque created by the opposing polarity of the U-shaped core (204);transmitting the rotation of the magnet (202) to a brush head (114) of the oral cleaning device (100) such that the brush head (114) rotates about a central axis of the oral cleaning device (100) for a predetermined time interval in a rotational movement pattern;after the predetermined time interval, phase-shifting a driving signal to the first (206) or the second (208) coil to generate a same polarity at the distal ends of the first (210) and second (212) arms of the U-shaped core (204);displacing the magnet (202) with a force created by the same polarity of the U-shaped core (204); andtransmitting the displacement of the magnet (202) to the brush head (114) of the oral cleaning device (100) such that the brush head (114) moves along another axis of the oral cleaning device (100) in a transient movement pattern.

2. The method of claim 1, further comprising phase-shifting the driving signal to the first (206) or the second (208) coil such that the phase-shifted driving signal interacts with first and second poles of the magnet (202) to generate the rotational movement pattern again.

3. The method of claim 1, wherein the phase-shift of the phase-shifted driving signal is 180 degrees to switch from the rotational movement pattern to the transient movement pattern.

4. The method of claim 1, wherein the transient movement pattern is characterized by a heightened amplitude that is higher than a later stabilized amplitude, and wherein the heightened amplitude is larger than any amplitude exhibited by the brush head (114) as it rotates about the central axis in the rotational movement pattern.- 22 -2025PF003805. The method of claim 1, wherein the another axis is substantially parallel to an axis of alignment of bristles of the brush head (114).

6. The method of claim 1, wherein each of the first and second driving signals comprises a time-varying voltage signal comprising a cyclical waveform and the predetermined time interval is a full cycle of the cyclical waveform.

7. A drivetrain assembly (122) of an oral cleaning device (100), the drivetrain assembly (122) comprising:a resonator (120) configured to transmit motion to a brush head (114), wherein the resonator (120) is configured to rotate about a central axis of the oral cleaning device (100) in a rotational movement pattern, and wherein the resonator (120) is configured to move along another axis of the oral cleaning device (100) in a transient movement pattern;a magnet (202) connected to the resonator (120);a coupling spring (214) connected to the magnet (202) and a brush head shaft (124) that transmits generated motion to the brush head (114);a U-shaped core (204) having a first arm (210) with a first coil (206) and a second arm (212) with a second coil (208); anda controller (130) configured to:generate and transmit first and second driving signals to the first (206) and second (208) coils wound around the first (210) and second (212) arms of the U-shaped core (204), respectively, wherein the first and second driving signals interact with first and second poles of the magnet (202), respectively, to generate the rotational movement pattern; andafter a predetermined time interval, phase-shift a driving signal to the first (206) or the second (208) coil, wherein the phase-shifted driving signal interacts with the first and second poles of the magnet (202) to generate the transient movement pattern.

8. The drivetrain assembly (122) of claim 7, wherein the controller (130) is further configured to phase-shift the driving signal to the first (206) or the second (208) coil, wherein the phase-shifted driving signal interacts with the first and second poles of the magnet (202) to generate the rotational movement pattern again.2025PF003809. The drivetrain assembly (122) of claim 7, wherein the phase-shift of the phase-shifted driving signal is 180 degrees to switch from the rotational movement pattern to the transient movement pattern.

10. The drivetrain assembly (122) of claim 7, wherein the transient movement pattern is characterized by a heightened amplitude that is higher than a later stabilized amplitude.

11. The drivetrain assembly (122) of claim 10, wherein the heightened amplitude is larger than any amplitude exhibited by the brush head (114) as it rotates about the central axis in the rotational movement pattern.

12. The drivetrain assembly (122) of claim 7, wherein the another axis is substantially parallel to an axis of alignment of bristles (116) of the brush head (114).

13. The drivetrain assembly (122) of claim 7, wherein each of the first and second driving signals comprises a time- varying voltage signal comprising a cyclical waveform.

14. The drivetrain assembly (122) of claim 13, wherein the predetermined time interval is a full cycle of the cyclical waveform.

15. The drivetrain assembly (122) of claim 7, wherein the first and second driving signals interact with the first and second poles of the magnet (202) by generating an opposing polarity at distal ends of the first (210) and second (212) arms and the phase-shifted driving signal interacts with the first and second poles of the magnet (202) by generating a same polarity at the distal ends of the first (210) and second (212) arms.

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