An added inertia resonant system (12) for a power toothbrush (10) comprises a drive shaft (16), a drive system (22), and at least one inertial weight member (24). The drive shaft (16) has a principal axis (26) that defines a center of rotation. The drive system (22) imparts a reciprocating motion to the drive shaft (16) about the principal axis (26). The at least one inertial weight member (24) couples to the drive shaft (16) and comprises a planar material having a complex shape balanced along an x-, y- and z-axis to enable the drive system (22) to achieve low power, high amplitude motion of the drive shaft (16) when placed under user loading. A method for providing added inertia in a resonant system for a power toothbrush is also disclosed.

The brush head of the toothbrush has filaments that are pointed at one end and led through clearances in the bristle carrier. These filaments have a length of about 10-20 mm. The tips of the pointed filaments produce a height profile other than that of a plane and the ends of the pointed filaments that are remote from the tips are melted.

An electric toothbrush according to the present disclosure includes: a shaft to which a brush is attached; a primary drive unit that operates the shaft to let the brush perform a cleaning motion; and a supplementary drive unit that enables the shaft to move eccentrically. Accordingly, the electric toothbrush can facilitate entry of bristles of the brush between teeth and improve performance of cleaning between the teeth.

A toothbrush is disclosed. The toothbrush includes a handle, a brush tip coupled to the handle, the brush tip including a plurality of bristles, a motor housed within the handle for operating the brush tip, a power source coupled to the motor, one or more lights coupled to the handle and viewable by a user when holding the handle, and a control module housed within the handle and in communication with the one or more lights, wherein the control module is configured to monitor a pressure exerted by the brush tip on a surface, determine when the exerted pressure exceeds a pressure threshold, and, in response to the exerted pressure exceeding the pressure threshold, activate the one or more lights to alert the user that the exerted pressure exceeds the pressure threshold.

An actuator (12) for a personal care appliance (10) having an eccentric core (21) to preload the actuator (12) to prevent rattling caused by detrimental reactionary forces. The eccentric core (21) includes a pole assembly (24) radially extending from a spindle 22 having at least a first set (25-1) and a second set (25-2) of pole members. The first set (25-1) has a greater length as measured from the center of the spindle 22 than the second set (24-2), reducing the magnet gap on one side of the spindle (22) to create an eccentric core and preload the actuator (12). Alternatively, the preload can be mechanically created by a set of bearings (28) disposed within housing (18) of the actuator 12, where the bearings (28) have a centerline (A3) offset from the principal axis (A1) of the housing (18).

A drivetrain assembly (100, 200) for a personal care device (10), the drivetrain assembly including a resonator (110) connected to a transmission component (24) configured to transmit oscillations to the removable attachment; and a drive coil (120) configured to oscillate the resonator in a first direction; where the drive coil is configured to generate an installation or removal signal in response to installation or removal of the removable attachment, the installation or removal of the removable attachment generating movement of the resonator in a second direction; and where the drivetrain assembly is configured to communicate the generated signal to a controller.

Provided is an automatic control type electric toothbrush, comprising a toothbrush head (20) and a toothbrush handle (10) connected by means of a driving shaft (12), wherein the toothbrush handle (10) is provided with a gesture sensor, a control module and a driving mechanism; and the control module can control the driving mechanism to drive the driving shaft (12), and same also drives the toothbrush head (20) to rotate clockwise or anticlockwise according to gesture data acquired from the gesture sensor, so that the toothbrush head (20) rotates in the direction from teeth root to dental crown. The automatic control type electric toothbrush can realize the purpose of automatically brushing teeth along the teeth, and can protect the gingivae, thus achieving automated treatment without manual control by a user, and therefore improving user experience.

A power toothbrush apparatus may include a body having a cavity and an opening leading to the cavity. An electric motor may be situated within the cavity and may include first and second biasing members; a stator casing situated between, and linearly biased by, the first and second biasing members, the stator casing may further include at least one opening and at least one electromagnet to generate a magnetic field; and a rotor which may have opposed ends and which may extend through the at least one opening of the stator casing, the rotor may further include an output shaft. The power toothbrush may further include a workpiece having a brush head coupled thereto and which may be coupled to one of the opposed ends of the output shaft.

A powered toothbrush includes a plurality of rows of bristle tufts that project through a perforated top shell of a hollow toothbrush head. Ends of individual bristles are held in buckets to form the tufts and the bristle ends opposite the bucketed ends are free (where the opposite ends contact the toothbrush user's teeth). The bucketed ends of the bristle tufts are captured within the internal space within the head but are not fixedly attached to any other toothbrush component or structure. This non-fixed attachment feature enables the bristle tufts to have multiple degrees of freedom (DoF) of motion with respect to the perforations in the top shell and can rotate, move axially, and tilt.