PATENT ABSTRACT
A toothbrush includes a housing having a handle and a toothbrush head, a pump having a pump chamber and a pump impeller or pump gear arranged in the pump chamber, and a motor driving the impeller or pump gear. An input port and an output port are connected to the chamber, the impeller causing a flow of a working fluid through the output port when the impeller is driven by the motor and the working fluid is supplied through the input port. The pump chamber has a circumferential wall defining a transverse cross section, the output port being connected to the pump chamber through the circumferential wall.

PATENT DESCRIPTION
[0001]    This application claims the benefit of Provisional Patent Application No. 61/626,863 filed on Oct. 3, 2011 titled “Electric Fountain Toothbrush” 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a manual toothbrush for brushing teeth with a pump configured to receive and redirect water from a faucet into a fountain stream for rinsing after brushing teeth. 
         [0004]    2. Description of Prior Art 
         [0005]    Brushing teeth is an essential part of any oral hygiene routine. However, if a person is not at home, a cup may not be available for oral rinsing after brushing. Furthermore, even if a cup is available, cups collect dirt and require frequent cleaning. The use of paper cups solves the problem of cleaning but is not environmentally friendly as it creates waste. Water directly from a faucet may also be used, but it is difficult to get the water from the faucet to a person&#39;s mouth without a cup. It is difficult to carry enough water for rinsing in cupped hands and it is even more difficult to obtain the water directly into a user&#39;s mouth from the faucet. 
         [0006]    U.S. Pat. Nos. 7,607,851 and 7,905,674, by the inventor of the present application, disclose fountain toothbrushes that include open or closed channels on the toothbrush housing to redirect water from a faucet back to the user in the form of a fountain. These channels are passive in that they depend at least in part on the strength of the flow discharged from the faucet. 
       SUMMARY OF THE INVENTION 
       [0007]    An object of the present invention is to provide a toothbrush that facilitates oral rinsing. 
         [0008]    The object is met by a toothbrush including a housing having a handle and a toothbrush head, a pump having a pump chamber and a pump impeller or pump gear arranged in the pump chamber, and a motor driving the impeller or pump gear. An input port and an output port are connected to the chamber, the impeller causing a flow of a working fluid through the output port when the impeller is driven by the motor and the working fluid is supplied through the input port. The pump chamber has a circumferential wall defining a transverse cross section of the pump casing, the output port being connected to the pump chamber through the circumferential wall. 
         [0009]    The output port includes a plurality of parallel channels according to one embodiment of the invention. The channels are separated by thin walls that extend longitudinally through the output port. The output port has an overall diameter of approximately 3.25 mm. The channel walls or fins may be injection molded as part of the housing. Alternatively, these walls may be part of an extruded part that is inserted into the output port. In one specific embodiment, the web includes at least two walls that are perpendicular to each other. It is also within the scope of the present invention to use at least one fin or rib anchored at only one end to straighten the water flow. However, it is preferable to have a plurality of smaller channels separated by thin walls measuring between 0.10 mm in thickness and 0.70 mm in thickness. 
         [0010]    According to an embodiment, the pump is a centrifugal pump. In this embodiment, the output port extends radially outward from the circumferential wall with respect to a rotating axis of the impeller. 
         [0011]    According to another embodiment, the output port extends perpendicular to the circumferential wall at the area in which the output port is connected to the chamber. 
         [0012]    The input port may be covered with a filter. The filter may, for example, be a plastic screen or a plastic grating and may be made of a less brittle and thereby less breakable alternative such as a hard rubber for improved safety. As such the impeller may also be made of a hard rubber. 
         [0013]    The toothbrush according to another embodiment may further include a switch for starting and stopping the motor. The switch is preferably a momentary switch that turns on the motor when pressed and turns off the motor when released. 
         [0014]    According to another embodiment, the input port comprises a channel configured to receive water flowing from a faucet and is on a same side of the housing as the output port. 
         [0015]    According to another embodiment, the housing comprises two injection molded parts, defining an upper part and a lower part of the pump chamber respectively. 
         [0016]    According to another embodiment, at least the motor the impeller are arranged in a pump casing, wherein the pump casing is inserted into the housing as a unit and overmolded in place by an overmolding material. The switch may also be inserted into the housing and overmolded in place. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The various features, functions, and advantages characterizing the invention will be better understood by reference to the detailed description which follows, when viewing the accompanying drawings, in which: 
           [0018]      FIG. 1  is a longitudinal sectional view of a toothbrush according to an embodiment of the present invention; 
           [0019]      FIG. 2  is a plan view of the toothbrush of  FIG. 1 ; 
           [0020]      FIG. 3  is a detailed sectional view of the components proximate a pump chamber in the toothbrush of  FIG. 1 ; 
           [0021]      FIG. 4  is a perspective view of an insert for the input port for the pump chamber of  FIG. 3 ; 
           [0022]      FIG. 5  is a perspective view of the toothbrush of  FIG. 1  during use; 
           [0023]      FIG. 6  is a perspective view of another embodiment of the toothbrush according to the present invention; 
           [0024]      FIG. 7  is a sectional view of the pump chamber of  FIG. 1 ; 
           [0025]      FIG. 8  is a sectional view of the pump chamber according to a further embodiment of the present invention; 
           [0026]      FIG. 9  is a longitudinal sectional view of a pump casing according to another embodiment of the present invention; 
           [0027]      FIG. 10  is an exploded view of a toothbrush with the pump casing of  FIG. 9 ; and 
           [0028]      FIG. 11  is a view of the toothbrush of  FIG. 10  with the pump casing overmolded in place. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    A toothbrush  100  according to an embodiment of the present invention is shown in  FIG. 1 . The toothbrush  100  has a housing  104  that includes an upper housing  104   a  and a lower housing  104   b . Toothbrush bristles  112  are arranged at a head portion of the toothbrush. The housing  104  defines a pump chamber  101  accommodating an impeller  105 , which is connected to a motor  102 . The motor  102  drives the impeller  105  to rotate and the impeller draws water from an input port  108  and ejects water through an output port  109 , as will be described in more detail below. The motor  102  comprises a coreless DC motor such as model 615 or 716. 
         [0030]    A battery  103  is arranged between two electric contacts  103   a ,  103   b  in the housing  104  and is connected to the motor  102  through a switch  122 . According to the present embodiment, the switch  122  is a momentary tactile switch that activates the motor when the switch is pressed and turns off the motor  102  upon release of pressure from the switch  122 . Although a momentary tactile switch is used in the present embodiment, any other type of electrical switch could be used to turn the motor  102  on and off. The switch  122  is arranged on a switch assembly  120 , which includes a base  123  on which the switch  122  is mounted. The base  123  is connected to the upper housing  104   a  using connecting elements such as threaded fasteners  124 , i.e., screws or bolts. A pushbutton  120  is mounted on the switch assembly  120  or on the upper housing  104   a  and is manipulated by a user to activate the switch  122 . 
         [0031]      FIG. 2  is a plan view showing the relative locations of the input port  108 , the output port  109 , and the pushbutton  121  on the upper housing  104   a  of the toothbrush. The input port  108  includes an upper rim portion  108   a  and side rim portions  108   b . Accordingly, the input port  108  is designed to guide or direct any water that strikes the upper housing  104   a  of the toothbrush  100  between the bristles  112  and the upper rim  108   a  into the pump chamber  101 . 
         [0032]      FIG. 3  is a more detailed view of the pump chamber  101  and surrounding components. The impeller  105  is arranged in the pump chamber  101  and is mounted on a motor shaft  132 , or a shaft drivably connected to the motor shaft, and is rotated by the motor  102 . The rotation of the impeller  105  causes water in the chamber  101  to be ejected through the output port  109 . The rotation of the impeller  105  also draws water into the chamber  101 . As shown in  FIG. 3 , the motor shaft  132  is inserted through a collar or bushing  130 . A seal  115  between the bushing  130  and the housing  104  prevents water from exiting the pump chamber  101 . 
         [0033]    As shown in  FIG. 3 , a filter  114  is arranged between the input port  108  and the chamber  101 . The filter  114  is in the form of a grating and is made, e.g., from injection molded plastic and/or rubber. The filter  114  prevents large objects from entering the pump chamber  101  to prevent damage to the impeller and to prevent injury to a user. In addition, the output port  109  includes an insert  109   a  (see also  FIG. 4 ) with longitudinal fins  109   b  that separate the output port into a plurality of channels  109   c . The insert can be an extruded plastic with a fin or web wall thickness t no greater than 1 mm. It is preferred that the fin or web wall thickness t is not greater than 0.65 mm. In a most preferred embodiment, the web wall thickness t is less than or equal to 0.2 mm. The overall diameter of the output port  109  is not greater than 5 mm and is preferably approximately 3.25 mm. All parameters are approximate and may vary based on manufacturing tolerances. 
         [0034]    The insert  109   a  as shown in  FIG. 3  may extend through part of the length of the output port  109 . However the fins  109   b  should extend at least one half of the length of the output port  109 . The fins  109   b  and channels  109   c  facilitate the formation of a fountain of water flow out of the output port  109  in a fountain. Without the insert  109   a , the water spreads more is not in the form of a fountain. Instead of using an insert  109   a , the fins  109   b  could be molded into the upper housing  104   b.    
         [0035]      FIG. 5  illustrates the intended use of the toothbrush  100 . A user hold the toothbrush  100  so that a stream of water  118  from a faucet enters the input port  108 . As shown in  FIG. 4 , the user&#39;s thumb presses pushbutton  121  to activate the motor and the pump ejects a fountain  129  of water from the output port  109 . 
         [0036]      FIG. 6  shows an alternative embodiment in which the input port  108 ′ and output port  109 ′ open on the lower side of the toothbrush  100 ′. In both the  FIG. 1  and  FIG. 6  embodiments, the pushbutton  121  for activating the switch may be arranged on the same side of the toothbrush as the housing or on the opposite side. 
         [0037]      FIG. 7  is a sectional view of the pump chamber  101  shown in  FIG. 1 . The circumferential wall  150  of the pump chamber  101  is circular. The water to be pumped enters the chamber  101  axially through the input port  108  and exits radially through the output port  109 . The impeller  105  in  FIG. 7  is depicted as an impeller of a centrifugal pump. The output port of a centrifugal pump is normally arranged tangential to the circumference of the pump chamber. However, for the purposes of the toothbrush body, it is better to be in the middle of the top of the toothbrush. 
         [0038]      FIG. 8  shows an alternative embodiment using a gear pump. The gear pump includes a drive gear  160  and an idler gear  162 . Water enters a suction port, i.e., input port  108 ″ from a front of the pump and ejects water out of the output port  109 . Here the axis of the drive gear is offset from a center of the toothbrush. Thus, the motor will have to be connected by a gear so that the motor is in the middle of the toothbrush. It is within the scope of the present invention to substitute a gear pump with a Lobe pump, a Rotary Vane pump, an axial pump or peristaltic pump. 
         [0039]      FIG. 9  shows a further embodiment in which the motor  102 , the impeller  105 , and the filter  114  are arranged in a pump casing  170 . Here the bushing  130  is not required because stresses are absorbed by the pump casing during installation. As shown in  FIG. 10 , the pump casing can be installed into a housing piece  204  as a unit. Likewise, the switch assembly  120  can be installed into the housing piece  204 . Once installed, the pump casing  170  and the switch assembly can be overmolded by a injection molded material  206 . In the embodiments of  FIGS. 10 and 11 , the housing includes a removable battery cover  180 . The cover  180  may alternatively comprise an opening at an end of the of the toothbrush. 
         [0040]    An offset weight can be placed on the shaft of the motor to cause the toothbrush to vibrate to create a Sonic Toothbrush with Pulsating Head and Built-in Power Fountain in one. 
         [0041]    A water jet waterpick flossing attachment comprising a pvc tube and molded plastic nozzle handle can be attached to the exit hole to convert the present invention into a small portable electric water jet flosser. 
         [0042]    The present invention has been described with reference to a preferred embodiments. It should be understood that the scope of the present invention is defined by the claims and is not intended to be limited to the specific embodiments disclosed herein. For example, elements of specific embodiments may be used with other embodiments without deviating from the scope of the present invention.