Brushing – scrubbing – and general cleaning – Machines – Brushing
Reexamination Certificate
2002-03-28
2004-08-24
Spisich, Mark (Department: 1744)
Brushing, scrubbing, and general cleaning
Machines
Brushing
Reexamination Certificate
active
06779215
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a power toothbrush having a bristle head coupled to a drive shaft. The drive shaft, and hence the bristle head coupled thereto, undergoes rotary oscillating motion about the axis of the drive shaft. The rotary oscillating motion is provided by a stepper motor. “Rotary oscillating motion” is sometimes referred to in the art as “angular displacement” or “sweep angle”.
2. Description of the Prior Art
To many people, the prevention of cavities in teeth is of utmost importance. The most common treatments for preventing cavities include brushing the teeth, flossing, and using fluoride rinses. Of these treatments, brushing the teeth is most common. Manual toothbrushes have dominated the toothbrush market for many years. Recently, power toothbrushes have increased in sales. The implication is that power toothbrushes may clean the teeth better than manual brushes.
Several varieties of power toothbrushes are sold commercially. The toothbrushes are typically powered by a motor which, in turn, is powered by a battery. In some instances, the batteries are re-chargeable. The motion of the toothbrush bristle head may vary. In a first design, the bristle head comprises a circular disk on which are mounted, generally parallel to the central axis of the disk, a plurality of bristles or bristle tufts. In one aspect of this first design, this bristle head is adapted to undergo continuous rotation about its central axis during use of the toothbrush. In a second aspect of this first design, the bristle head is adapted to undergo repeating partial rotation about its central axis, i.e., the bristle head travels a limited distance along an arc of a circle in one direction (for example, counterclockwise) after which the bristle head travels along the same arc in the opposite direction (for example, clockwise).
In a second design, the bristle head comprises a base which is generally rectangular in configuration and has a longitudinal axis. The bristle head base carries bristles or bristle tufts which are secured perpendicularly to its surface and are usually arranged in longitudinally extending rows. In a first aspect of this second design, the bristle head is adapted to undergo continuous reciprocating motion whereby the bristle head moves forward and backward alternately in a direction parallel to its longitudinal axis. In a second aspect of said second design, the bristle head is adapted to undergo oscillating motion about its longitudinal axis, i.e., the bristle head, when viewed in front end elevation, moves in a back-and-forth, arcuate path in the fashion of a pendulum. Such motion is also referred to as rotary oscillation motion.
There is a continuing effort to provide power toothbrushes that clean teeth better. The term “cleaning teeth better” means cleaning the surface of the teeth better, cleaning between the teeth better, cleaning behind the teeth better, or some combination thereof.
European Patent Application 0 968 686 teaches a power toothbrush with a toothbrush head that has oscillating motion about its longitudinal axis, i.e., rotary oscillating motion. A relatively complex transmission assembly is utilized to convert the rotational movement of an output shaft of a motor into rotary oscillating motion at the bristle head of the toothbrush.
It would be advantageous to have a power toothbrush having a bristle head which undergoes rotary oscillating motion, which said oscillating motion is provided by either a simplified transmission assembly or with no transmission assembly at all.
SUMMARY OF THE INVENTION
The present invention provides a power toothbrush comprising:
an elongate body defining a handle and having an interior cavity formed therein, said elongate body having a distal end and a proximal end;
an elongate housing having a proximal end and a distal end, said housing including a plurality of bristles at its distal end;
a stepper motor disposed within the interior cavity of the elongate body, said stepper motor including an output shaft providing rotary oscillating motion; and
means for operatively connecting said elongate housing to the output shaft of said stepper motor.
In one embodiment of the present invention, the end portion of the output shaft of the stepper motor has a rectangular cross-section and the elongate housing comprises a matching rectangular slot at its end. The elongate housing and the stepper motor output shaft are operatively connected by inserting the output shaft having the rectangular cross-section into the rectangular slot of the elongate housing. It will be understood by those skilled in the art that other cross-sectional configurations could be employed. For example, the output shaft could be triangular in configuration and the elongate body would have a triangular slot at its distal end to receive the triangularly shaped stepper motor output shaft in operative engagement.
In a second embodiment of the present invention, the output shaft of the stepper motor is connected, by a coupling mechanism, to a connector shaft which extends beyond the distal end of the elongate body. The connector shaft in turn is secured to the elongate housing comprising the toothbrush bristle arrangement. In use, the rotary oscillating motion of the output shaft of the stepper motor is transmitted, via the coupling mechanism, to the elongate housing comprising the aforementioned toothbrush bristle arrangement whereby the bristle arrangement undergoes the same rotary oscillating motion as the output shaft of the stepper motor.
In each of the aforementioned embodiments, the stepper motor may be controlled by electronic controller means which regulates the motion of the output shaft of the aforementioned stepper motor. In other words, the electronic controller means is operatively connected to the stepper motor and controls that motor in such fashion that the output shaft thereof is provided with the desired rotary oscillating motion.
The power toothbrushes of the present invention may further include means for insuring that the desired rotary oscillating motion, i.e., sweep angle, of the stepper motor output shaft is achieved at start-up or is maintained or restored in the event excessive force is applied to the toothbrush during use.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The power toothbrushes of the present invention comprise an elongate body having a proximal end and a distal end. The elongate body defines a handle portion for gripping the power toothbrush and has an interior cavity formed therein which extends from its proximal end to its distal end. The elongate body may be made of any material suitable for power toothbrush bodies. Such materials include, but are not limited to, polyolefins, such as polyethylene and polypropylene; polycarbonate; polyurethanes; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polycaprolactone; polyamides, such as nylon 6 and nylon 12; cellulose acetate propionate; styrene acrylonitrile copolymers; alkyl benzyl styrene copolymers; and the like. The elongate body may be made by any process known in the art, such as injection molding, machine forming, and stamping. Injection molding is particularly useful.
As indicated earlier herein, the elongate body defines a handle and has an interior cavity formed therein. The interior cavity holds a source of energy for the motor, such as a battery. Solar cells or fuel cells may also be utilized as energy sources. Any conventional battery may be utilized as the energy source. The battery may be re-chargeable. The battery may be re-charged by removing the battery from the toothbrush and connecting the battery to a re-charging station, as is known in the art. Alternatively, the battery may be left in the toothbrush and the toothbrush placed in a suitable re-charging station for recharging of the battery.
An elongate housing having a proximal end and a distal end is operatively connected to the output shaft of the stepper motor and includes a toothbrush bristle head at the distal end thereof.
Hartman Frederick R.
Hull, Jr. Raymond J.
Tessarotto Luiz Arthur Bonaci
Mc-Neil-PPC, Inc.
Spisich Mark
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