Multi-function switch for an oral care appliance

This invention relates generally to an oral care appliance which uses pressurized gas and liquid to accomplish teeth cleaning, and more specifically concerns a switch assembly which actuates multiple functions of the appliance.

In many oral care appliances, including specifically power appliances using pressurized gas and liquid, several individual, separate functions must be controlled and sequenced for proper operation of the appliance. Typically, this requires the use of a plurality of individual switches and/or other actuators in a particular sequence. Significant operational capability is achieved with such a system, but at additional expense and complexity. It would thus be desirable to have a single switch assembly which can control a plurality of individual functions in a correct sequence so as to reduce cost as well as improving the reliability.

Accordingly, a multi-function switch for an oral care appliance is disclosed which includes a source of compressed gas, a source of liquid and a mixing chamber for mixing the gas and the fluid to produce a stream of fluid droplets directed out through a nozzle assembly, comprising: a switch housing having a hollow chamber therein; an actuation assembly which includes a stem portion having an O-ring assembly around the periphery thereof; an inlet channel connecting the source of compressed gas to the hollow chamber in the housing; an outlet channel connecting the hollow chamber to the mixing chamber; wherein the O-rings are positioned on the stem relative to the inlet channel and the outlet channel such that in a first position of the actuation assembly, one O-ring seals the inlet channel at the chamber and, as the actuation assembly is actuated, the stem moves such that the outlet channel at the chamber is or continues to be sealed by another O-ring, and the inlet channel is uncovered, allowing into the chamber an amount of gas, while at that point or thereafter a pump is activated to move liquid into the mixing chamber; wherein when the actuation assembly is thereafter released to return to its first position, the inlet channel is first sealed and the outlet channel is subsequently uncovered, allowing the gas in the chamber to rapidly move into the mixing chamber to mix with the liquid therein, to produce a stream of fluid droplets which are directed to and out a nozzle portion of the appliance.

FIG. 1 is a longitudinal cross-sectional view of an oral care appliance incorporating a multi-function switch disclosed herein.

FIG. 2 is a cross-sectional view of the multi-function switch portion of the appliance of FIG. 1 .

FIG. 1 shows an oral care appliance which is particularly adapted for cleaning interproximal areas of the teeth, but which can also clean the exposed surfaces of the teeth as well. The appliance, shown generally at 10 , includes a housing 12 , with an end or base cap/plug 14 at a rear end and a nozzle assembly 16 extending from the other end. The appliance 10 in general operation uses a source of compressed gas, such as a CO 2 cartridge 18 , and a source of liquid, stored in a reservoir 20 , to produce a stream of fluid droplets directed through nozzle 16 for use in oral cleaning, including cleaning the interproximal areas of the teeth. Such an appliance is in general well-known.

In the embodiment shown, a multi-function switch 24 , which function in some respects like a valve, is used to control a metered, i.e. fixed, amount of pressurized gas from cartridge 18 and liquid from reservoir 20 into a mixing chamber 26 , where the liquid is mixed with the pressurized gas to produce the stream of liquid droplets, which are then directed through nozzle assembly 16 to the teeth.

Switch assembly 24 includes a housing 28 having a hollow interior chamber 30 therein. Housing 28 is configured to extend laterally across the longitudinal dimension of the appliance, but other arrangements and configurations for the switch 24 are possible.

Mounted in housing 28 is a button assembly 32 which is biased by a spring 34 in a first position. Button assembly 32 includes a button 36 which is generally round and otherwise configured to conveniently accommodate a finger of the user. In the first position of the button assembly, button 36 is positioned slightly away from the housing. Button assembly 32 also includes a stem 40 which fits into chamber 30 of housing 28 in an air-tight relationship. Operation, i.e. pushing, of button 36 in a direction toward housing 28 , moves stem portion 40 within housing 28 . Mounted in the peripheral surface of stem are several O-rings 42 - 42 ( FIG. 2 ) at spaced intervals along the stem. In the embodiment shown, there are four separate O-rings 42 - 42 . The O-rings 42 extend from the surface of stem 40 to the interior wall 44 of chamber 30 .

Extending from a forward end 46 of the CO 2 cartridge 18 is a hollow needle 48 . Hollow needle 48 mates with an inlet channel 50 which extends through the wall 49 of housing 28 of the switch assembly to chamber 30 . In the embodiment shown, channel 50 is positioned at an angle through wall 49 of housing 28 . When button assembly 32 is in its first (non-operated or rest) position, one of the O-rings 42 covers, i.e. seals, the opening of inlet channel 50 into chamber 30 , preventing any gas from the CO 2 cartridge from entering the chamber.

Extending through the wall 49 of housing 28 on the opposite side of chamber 30 is an outlet channel 52 . Outlet channel 52 is also angled and opens into chamber 30 at a different longitudinal point than inlet channel 50 along the length of chamber 30 . In the embodiment shown, the inlet and outlet channels are circular in cross-section, approximately 2 millimeters in diameter, although this may be varied. When button assembly 32 is in its first (non-operated) position, the opening of outlet channel 52 from chamber 30 is open, although in another arrangement, an O-ring 42 closes off the outlet channel 52 in the first position of the button assembly.

The forward end 56 of liquid reservoir 20 is connected through a fluid channel 58 to mixing chamber 26 . Reservoir 20 includes a manual pump 60 , by which liquid from the reservoir is moved through channel 58 into mixing chamber 26 . Pump 60 is positioned so that an actuating portion 62 thereof extends into chamber 30 a small distance for contact with a distal end 64 of stem 40 when button assembly 32 is operated.

In operation, when button assembly 32 is in its first (non-operated/rest) position, inlet channel 50 at the entrance to chamber 30 is closed off by one O-ring 42 . the O-rings 42 are mounted on stem 40 such that when button 36 is pushed, moving to its second, operated position, another of the O-rings 42 first seals the exit to outlet channel 52 . This is accomplished while the inlet channel 50 into chamber 30 is sealed. Alternatively, outlet channel could have already been sealed and remains sealed while button 36 is pushed. Subsequent to outlet channel 52 being sealed, inlet channel 50 is opened, by virtue of the O-ring at that channel moving away from that channel opening as stem 40 moves within the chamber due to the pushing of the button 36 . At this point, a specific, metered volume of gas enters into the chamber 30 through angled inlet channel 50 . The defined volume of the chamber results in a precise amount of gas entering the chamber before the pressure is equalized between the chamber 30 and the cartridge.

The operation of button assembly 32 also results in distal end 64 of stem 40 actuating pump 60 , resulting in a selected amount of liquid being moved from reservoir 20 directed through channel 58 into mixing chamber 26 .

The button 36 is then released, which allows spring 34 to return the button assembly 32 to its first position, which results first in one O-ring 42 sealing the inlet channel 50 again and then, subsequent thereto, one O-ring 42 which previously sealed outlet channel 52 moving away from the outlet channel, resulting in the angled outlet channel being opened. In an alternative arrangement, an outlet slot in the outlet of the chamber is provided to receive the O-ring. In this arrangement, the O-ring is forced by the high pressure gas present in the chamber into the slot, opening the path for the gas to flow into the outlet instantaneously, such that the opening of the outlet is independent of the action of the user after gas has entered the chamber. This results in the gas present in chamber 30 expanding out through channel 52 into mixing chamber 26 , where the mixing of the pressurized gas from the chamber 30 and the liquid from reservoir 20 results in a stream of liquid droplets which proceed from the mixing chamber 26 into the proximal end 66 of nozzle assembly 16 . The liquid droplets continue through the nozzle assembly 16 to the outlet therefrom, for use in cleaning of teeth. The nozzle assembly 16 could also include a guidance tip which is designed to fit in the interproximal areas of the teeth.

In addition to the above, switch 10 could be configured to accomplish other functions as it is moved from its first (rest) to its second (operative) position and vice versa. For instance, electrical contacts could be positioned within chamber 30 volume so that movement of the button assembly could connect the contacts to operate another switch or activate a circuit to accomplish other functions, such as energizing an LED or status indicator or other similar function.

Hence, a switch assembly has been disclosed which, in operation, will produce a sequence of specific operations of the appliance. A single switch structure can thus accomplish a plurality of different functions, in a desired sequence.

Although a preferred embodiment of the invention has been disclosed for purposes of illustration, it should be understood that various changes, modifications and substitutions may be incorporated in the embodiment without departing from the spirit of the invention which is defined by the claims which follow.