Abstract: The present disclosure is directed to a low-cost toothbrush with a simple-to-manufacture design that provides a tapping motion of the brush head. In an embodiment, a dental cleaning device includes an eccentric rotating mass motor and a drive shaft mechanically coupled to the motor. A spring element is mounted to the drive shaft in a configuration in which it acts in a direction perpendicular to the axis of the drive shaft. The spring element and drive shaft form an assembly having a resonant frequency. A power source supplies to the motor power sufficient to cause the motor to operate near the resonant frequency of the assembly.

Abstract: The personal care appliance (10) comprises a handle/housing (20), a workpiece assembly (12), a motor assembly (18) which is mounted to the handle for driving the workpiece assembly and a secondary resonator (30) connected to the motor assembly or the handle, the secondary resonator comprising a spring mass assembly characterized in that at resonant operation thereof, vibrations produced by action of the motor assembly which would otherwise be transmitted to the handle, are significantly reduced/cancelled.

Abstract: The spray assembly for a droplet spray teeth cleaning system includes a guidance member at the end thereof. The spray assembly includes a nozzle through which a spray of liquid is directed to the teeth for cleaning. The guidance member is configured and mounted relative to the nozzle to provide a selected standoff distance between the nozzle and the teeth and includes a portion which is configured to fit in the interproximal space between adjacent teeth and gums, or against the frontal portions of the teeth, so that the user knows the location of the spray relative to the teeth.

Abstract: The system periodically measures the battery voltage of the toothbrush and the current in a stator portion of the motor for the appliance. The amplitude of movement of the toothbrush workpiece is determined from the measured stator current. A circuit/control program changes the duty cycle or pulse width of the drive signal from the motor if the battery voltage drops below a first threshold value and a circuit or control program changes the drive frequency of the appliance if the amplitude of the workpiece movement falls below a first threshold value. A circuit/control program terminates the operation of the toothbrush if the voltage drops below a second threshold value or if the amplitude drops below a second threshold value, both of which are less than the respective first thresholds.

Abstract: The spray assembly for a droplet spray teeth cleaning system includes a guidance member (40, 56, 80, 86) at the end thereof. The spray assembly includes a nozzle (24) through which a spray of liquid is directed to the teeth for cleaning. The guidance member is configured and mounted relative to the nozzle to provide a selected standoff distance between the nozzle and the teeth and includes a portion which is configured to fit in the interproximal space between adjacent teeth and gums, or against the frontal portions of the teeth, so that the user knows the location of the spray relative to the teeth.

Abstract: A workpiece system with a reciprocating motion which includes a motor assembly for producing an output drive signal with a periodic force pulse. The drive signal is coupled to a driven member assembly through a magnetic arrangement, wherein the driven member assembly has a workpiece mounted thereon with a return spring assembly. The driven member assembly has a resonant mechanical frequency. As the RPM of the motor increases from zero following startup, the drive signal frequency increases to the point very near resonance, where the energy from the drive signal is transferred into the reciprocating motion of the driven assembly, producing an effective amplitude of workpiece motion.

Abstract: The personal care appliance (10) comprises a handle/housing (20), a workpiece assembly (12), a motor assembly (18) which is mounted to the handle for driving the workpiece assembly and a secondary resonator (30) connected to the motor assembly or the handle, the secondary resonator comprising a spring mass assembly characterized in that at resonant operation thereof, vibrations produced by action of the motor assembly which would otherwise be transmitted to the handle, are significantly reduced/cancelled.

Abstract: The personal care appliance drive system includes a pair of linear actuators capable of operating both in an opposing phase mode or in a parallel (in-phase) mode. The system includes a motion converter assembly which converts the opposing phase action of the two linear actuators into a rotational action of an output drive shaft and converts in-phase action to a translation motion of the output shaft or to drive another function of the appliance, such as a pump. The motion converter, operating simultaneously in an opposing phase mode and in-phase modes, produces a complex motion of the workpiece.

Abstract: The personal care appliance drive system includes a pair of linear actuators capable of operating both in an opposing phase mode or in a parallel (in-phase) mode. The system includes a motion converter assembly which converts the opposing phase action of the two linear actuators into a rotational action of an output drive shaft and converts in-phase action to a translation motion of the output shaft or to drive another function of the appliance, such as a pump. The motion converter, operating simultaneously in an opposing phase mode and in-phase modes, produces a complex motion of the workpiece.