Abstract:
A method and the resulting product for optimizing the configuration of a mouthpiece for cleaning teeth in which the configuration of the mouthpiece is optimized to the oral geometry of individual users. The method includes a first step (26) of producing a digital scan of the oral geometry of the individual user and then producing a rigid shell (30) for the mouthpiece substantially matching the digital scan. The configuration of the resulting mouthpiece is characterized by the outer surface of the shell not extending from the buccal surface of the individual teeth more than 7 mm (31); further, by the rear edge of the shell not contacting the tissues to the rear of the rearmost teeth (36), and still further by no more than a 2 mm overlap into the gum line (36), when the mouthpiece is operatively positioned in the user's mouth.
Abstract:
The mouthpiece assembly includes a receptacle (12) for receiving teeth therein, with bristles (24) mounted thereon for contacting and cleaning the teeth. The receptacle and the bristles cover at least 4 cm. A drive train (20) drives the receptacle such that the bristles move substantially at right angles toward and away from the surfaces of the teeth, the drive train including a motor (22) which produces sufficient force to produce a minimum bristle tip threshold pressure of 6 Newtons per cm and a maximum of 85 Newtons per cm.
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 apparatus for converting side-to-side to rotational motion for a workpiece includes a spring assembly with a movable base mounting element which is driven in a slightly arcuate reciprocal side-to-side motion and a fixed mounting element spaced apart from the base element and mounted in the appliance so that it does not rotate or move in operation of the apparatus. A spring member, such as two planar leaf springs positioned at an angle to each other, is mounted between the movable base element and the fixed mounting element. A drive shaft member extends from the movable base element through the fixed mounting element and beyond. A workpiece such as a brushhead is mounted on the distal end of the drive shaft. The spring member is configured so that it is substantially less resistant to twisting action than bending action, such that the side-to-side motion of the base element results in rotation of the workpiece.A method for tuning resonant spring assembly systems used in appliances such as power toothbrushes, particularly leaf spring systems, includes the step of measuring the frequency-dependent amplitude of the appliance workpiece, and then removing a portion of the spring member so as to decrease its spring rate sufficiently that the resonant frequency of the spring member closely approximates the drive frequency of the appliance.
Abstract:
An adaptive system for a personal care appliance, such as a power toothbrush, having a workpiece which is driven through an amplitude of motion by a drive mechanism which includes a stator member includes a circuit (13) for measuring average electrical current through the stator member and stored information (19) in the personal care appliance which relates the average current values through the stator during operation of the device to corresponding amplitude of motion of the workpiece. A processor (17) utilizing a stored program adjusts the operating frequency to produce a stator current value which correlates to the desired amplitude of motion of the workpiece.
Abstract:
An adaptive system for a personal care appliance, such as a power toothbrush, having a workpiece which is driven through an amplitude of motion by a drive mechanism which includes a stator member includes a circuit (13) for measuring average electrical current through the stator member and stored information (19) in the personal care appliance which relates the average current values through the stator during operation of the device to corresponding amplitude of motion of the workpiece. A processor (17) utilizing a stored program adjusts the operating frequency to produce a stator current value which correlates to the desired amplitude of motion of the workpiece.
Abstract:
A method for tuning resonant spring assembly systems used in appliances such as power toothbrushes, particularly leaf spring systems, includes the step of measuring the frequency-dependent amplitude of the appliance workpiece, and then removing a portion of the spring member so as to decrease its spring rate sufficiently that the resonant frequency of the spring member closely approximates the drive frequency of the appliance.
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 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 adapting system for a resonant drive appliance includes a circuit for measuring the back EMF induced in the stator coil of the motor following turn-off of the appliance. The frequency of the back EMF signal is determined from the zero crossings of the EMF signal. The determined frequency is then compared with a running average of previous frequency determinations, and the drive frequency of the appliance is adjusted if the difference between the compared frequencies is greater than a threshold value, e.g. 1 Hz.