Humidifier with stacked reservoir

A humidifier with a stacked reservoir system includes a first wettable wick adapted to humidify an air stream and a first reservoir for holding water. The first reservoir is located in a position adapted to wet the first wick by capillary action and shaped to accommodate sufficient air flow through the humidifier. The humidifier includes a second wettable wick adapted to humidify the air stream and a second reservoir for holding water. The second reservoir is located in a position adapted to wet the second wick by capillary action and adapted to capture water overflowing from the first reservoir.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates generally to humidifiers, and more
 specifically to a stacked reservoir system for humidifiers.
 2. Description of the Related Art
 FIG. 1 illustrates the operating principle of a wick system of a prior art
 humidifier 10. A stream of dry air 12 enters an intake 14 of the
 humidifier 10. The stream of dry air 12 passes through or over a wet wick
 16 and picks up additional moisture to form a humid stream of air 18. The
 humid stream of air 18 leaves the humidifier by an output 19. One end of
 the wick 16 makes contact with water in a reservoir 20. Water from the
 reservoir 20 replenishes water carried away from the wick 16 by the stream
 of air 18.
 Referring to FIG. 1, the wick 16 is wetted by a natural wicking action,
 i.e., capillary action. The wick 16 may be constructed from a variety of
 wettable materials, e.g., paper, provided that a substantial area of wick
 16 becomes wetted through capillary action when a portion is placed in
 contact with water. Then, the capillary action draws water into the wick
 16 to replenish moisture continually carried away by the stream of air 18.
 FIG. 2 illustrates a prior art wick system 22 that uses a continuous water
 flow 24 to keep the wick 26 wet and capable of humidifying a stream of dry
 air 28. A pump 30 continually refills a reservoir 32 with water. Gravity
 produces the water flow 24 from the holes 23 in the bottom of the
 reservoir 32. The water flow 24 moves from the top to the bottom of the
 wick 26. Excess water drips off the wick 26 into a reservoir 34 positioned
 below the wick 26. The pump 30 draws water from the reservoir 34 to refill
 the reservoir 32. The wick system 22 uses a cyclic flow to keep the wick
 26 wetted. The height of the wick 26 may be higher than height of the wick
 16 of FIG. 1, which is wetted solely by capillary action.
 Referring to FIG. 2, the use of a continuous flow to keep the wick 26
 wetted introduces certain problems. The water flow 24 continually carries
 minerals contained in the wick 26 into the reservoir 34, the pump 30, and
 the reservoir 32. These deposits accumulate and lead to a need for
 periodic cleaning. Additionally, the water flow 24 through the holes 23
 causes occasionally water splashing. The water splashing can create an
 annoying noise that is undesirable in a domestic humidifier. The splashing
 also deposits minerals, contained in the water, on extraneous parts. The
 splashing noises and accumulation of minerals, leached out of the wick 26,
 make the wick system 22 less desirable.
 The present invention is directed to overcoming, or at least reducing the
 effects of, one or more of the problems set forth above.
 SUMMARY OF THE INVENTION
 In one aspect of the present invention, a humidifier is provided. The
 humidifier includes a first wettable wick adapted to humidify an air
 stream and a first reservoir for holding water. The first reservoir is
 located in a position adapted to wet the first wick by capillary action
 and shaped to accommodate sufficient air flow through the humidifier. The
 humidifier includes a second wettable wick adapted to humidify the air
 stream and a second reservoir for holding water. The second reservoir is
 located in a position adapted to wet the second wick by capillary action
 and adapted to capture water overflowing from the first reservoir.
 In another aspect of the present invention, a method of humidifying air is
 provided. In accordance with this method, a plurality of water trays in a
 humidifier, at least one of which water trays is positioned above all
 other water trays, arc separately, manually filled, and dry air is moved
 through a plurality of wicks, each of which is associated with one of the
 plurality of water trays.

While the invention is susceptible to various modifications and alternative
 forms, specific embodiments thereof have been shown by way of example in
 the drawings and are herein described in detail. It should be understood,
 however, that the description herein of specific embodiments is not
 intended to limit the invention to the particular forms disclosed, but on
 the contrary, the intention is to cover all modifications, equivalents,
 and alternatives falling within the spirit and scope of the invention as
 defined by the appended claims.
 DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
 Illustrative embodiments of the invention are described below. In the
 interest of clarity, not all features of an actual implementation are
 described in this specification. It will of course be appreciated that in
 the development of any such actual embodiment, numerous
 implementation-specific decisions must be made to achieve the developers'
 specific goals, such as compliance with system-related and
 business-related constraints, which will vary from one implementation to
 another. Moreover, it will be appreciated that such a development effort
 might be complex and time-consuming, but would nevertheless be a routine
 undertaking for those of ordinary skill in the art having the benefit of
 this disclosure.
 An embodiment of the present invention is illustrated in FIGS. 3A, 3B and
 4. A humidifier 310 includes a cabinet 320. A first wick 312 and second
 wick 316 are located within the cabinet 320, with the first wick 312
 positioned above the second wick 316 when the humidifier 310 is viewed
 from the front, as shown in FIG. 3A. A first reservoir 314 is positioned
 under the first wick 312 such that the bottom edge of the first wick 312
 may be in contact with the water held by the first reservoir 314, thereby
 wetting at least a portion of the first wick 312 by capillary action. A
 second reservoir 318, which may also simply be the lower portion of the
 cabinet 320, is positioned under the second wick 16 such that the bottom
 edge of the second wick 316 may be in contact with the water held by the
 second reservoir 318, thereby wetting at least a portion of the first wick
 316 by capillary action. For a general form of humidifiers with "stacked"
 plurality of wicks and associated water trays, see the present inventors'
 commonly assigned and copending application, Ser. No. 09/122,905, filed on
 Jul. 27, 1998, now U.S. Pat. No. 5,975,502 which application is
 incorporated herein by reference.
 The rim 322 of the second reservoir 318 in the embodiment encompasses the
 rim 324 of the first reservoir 314 when the humidifier 310 is viewed from
 top, as illustrated in FIG. 3B, so that any water flowing over the rim 324
 of the first reservoir 314 is captured by the second reservoir 318.
 The first reservoir 314 in the embodiment has three interconnected water
 channels 314a, 314b and 314c, which from a U-shape when viewed from above
 and are disposed near the walls of the cabinet 320, as illustrated in FIG.
 3B. This configuration ensures substantially unobstructed flow of air from
 the second wick 316 to the top of the humidifier 310 through the space at
 the center of the U-shape while allowing the first reservoir 314 to store
 a sufficient amount of water so that the time interval between necessary
 refilling of the second reservoir 316 is maximized.
 In operating the humidifier 310 of the illustrated embodiment, water is
 poured into the first reservoir 314 so that at least a portion of the
 first wick 312 is in contact with the water held by the first reservoir
 314. At least a portion of the first wick 312 is wetted by capillary
 action. Water is also poured into the second reservoir 318 so that at
 least a portion of the second wick 316 is in contact with the water held
 by the first reservoir 318. At least a portion of the second wick 316 is
 wetted by capillary action. A stream of air is passed from outside of the
 humidifier 310 through the front of the humidifier 310, through both wicks
 312 and 316, where the stream of air carries moisture away from the wetted
 portions of the wicks 312 and 316, and through the top of the humidifier
 310, into the area to be humidified. The reservoirs 314 and 318 may be
 refilled as necessary.
 The particular embodiments disclosed above are illustrative only, as the
 invention may be modified and practiced in different but equivalent
 manners apparent to those skilled in the art having the benefit of the
 teachings herein. Furthermore, no limitations are intended to the details
 of construction or design herein shown, other than as described in the
 claims below. It is therefore evident that the particular embodiments
 disclosed above may be altered or modified and all such variations are
 considered within the scope and spirit of the invention. Accordingly, the
 protection sought herein is as set forth in the claims below.