Abstract:
An electric warm-air humidifier consisting of a base, a boiler tray supported on the base, a heating element, a liquid supply supported on the base and having a discharge opening communicating with the boiler tray and adapted to maintain a given level of liquid therein and a vapor chimney supported on the base having a receiving end communicating with the boiler tray so as to receive vapor therefrom and a discharge end for discharging the vapor received from the boiler tray. Also included is an electrical supply for supplying electrical energy to the heating element and a switch mounted on the heating element and adapted to deactivate the electrical supply in response to separating movement between the vapor passage and the base assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to humidifiers, and more particularly to a blowerless warm-air humidifier. 
     2. Description of the Prior Art 
     One of the problems with portable humidifiers, which include a vapor chamber in the form of a chimney, a boiler tray, an electrical supply connected to a heating element in the boiler tray, and water reservoirs, is the ability to thoroughly clean the elements of the humidifier. 
     Portable humidifiers are generally modular and the various parts can easily be disassembled and reassembled for operation. However there are still too many areas of the components that cannot be properly cleaned and are subject of mineral deposits and bacteria built up. 
     Attempts have been made to overcome certain of these problems. U.S. Pat. No. 5,339,383 Marino 1994 discloses a humidifier with electrical components located about the lower pan in which the water is heated. An electrical interlocks allows access to the interior only after the electrical power has been unplugged. U.S. Pat. No. 5,014,338 Glucksman issued in 1991 as well as U.S. Pat. No. 5,111,529 also to Glucksman issued in 1992 show motor driven blowers in a portable air humidifier where the water tray is removable for cleaning. 
     However in any of these patents it has still been found difficult to access areas for cleaning, such as the vapor chamber, etc. 
     SUMMARY OF THE INVENTION 
     It is an aim of the present invention to provide a portable humidifier which is made of separable components which can be easily disassembled and assembled for cleaning purposes. 
     The invention is a humidifier including a base, a boiling tray removably mounted to the base which incorporates a heating element, a liquid supply means supported on the base and having a discharge opening communicating with the boiling tray and adapted to maintain a given level of liquid therein, a vapor passage supported on the base and having a receiving end communicating with the boiling tray and a discharge end for discharging the vapor received from the cavity. Also included is an electrical supply for supplying electrical energy to the heater and a switch mounted on the heating element and adapted to deactivate the electrical power to the heater in response to a separating movement between the vapor passage and the base assembly. 
     When electrical power is supplied to the heating element the water in the boiling tray rapidly reaches the boiling temperature and begins to vaporize. As this vapor rises in the vapor passage, air is drawn through the air inlet, through the plenum formed beneath the boiling tray and upward through the chimneys formed in the boiling tray. This cool room air mixes with the vapor in the vapor passage thus lowering the temperature of the discharges air/vapor mixture to a safe and comfortable level. 
     The humidifier of this invention has advantages over prior art warm-air humidifiers for a number of reasons: 
     i) Compared with other warm-air humidifiers which use a motor driven fan to provide air mixing, the humidifier described herein is quieter, simpler and less costly to manufacture. 
     ii) Compared with units which mount the heating element in a removable evaporation chamber, the humidifier described herein is simpler in construction and easier to clean. Humidifiers of this type have only the bottom surface of the heating element accessible and since all of the electrical parts are enclosed in the same evaporation housing, care must be taken to prevent water entering the electrical housing during cleaning. The boiling chamber described herein is completely removable from the base to facilitate cleaning. 
     iii) Compared with units which mount the boiling tray (sealed to the base) and electrical supply in the base, the humidifier described herein is easier to clean and safer since water leaks in the above mentioned units can cause electrical shorts and associated damage. All electrical connections in the humidifier described herein are above the water level of the tray and the overflow level of the base. 
     An element of this invention is the boiling tray which incorporates through holes in its construction to facilitate the air mixing which results in safe discharge vapor temperatures. The boiling tray can be constructed in a variety of ways to facilitate ease of removal and ease of cleaning. 
     a) The boiling tray can be constructed of stamped sheet metal, (e.g. stainless steel), with the heating element mounted in close thermal contact. Moreover the surface of the boiling tray can be coated with a non-stick material to further facilitate removal of mineral deposits which accumulate with use. 
     b) The boiler tray can be constructed of injection molded plastic. In this alternative configuration the plug-in heating element is immersed in the water contained in the tray. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration, a preferred embodiment thereof, and in which: 
     FIG. 1 is a front elevation partly cut away showing an embodiment of the present invention; 
     FIG. 2 is a top plan view of the embodiment shown in FIG. 1; 
     FIG. 3 is a vertical cross-section taken through lines  3 — 3  of FIG. 2; 
     FIG. 4 is a vertical cross-section taken along lines  4 — 4  of FIG. 2; 
     FIGS. 5 a ,  5   b , and  5   c  are fragmentary enlarged vertical cross-sections of different portions of the electrical connectors; 
     FIG. 6 a  is a top plan view of the boiling tray of the present embodiment; 
     FIG. 6 b  is a vertical cross-section taken along lines b—b of FIG. 6 a ; and 
     FIG. 6 c  is a vertical cross-section taken along lines a—a of FIG. 6 a.   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, particularly of FIGS. 1 to  3 , the humidifier includes a vapor chamber housing or chimney  12  sitting on a base  16  which also supports a pair of water reservoirs  14   a  and  14   b . The chimney  12  and water reservoirs  14   a  and  14   b  are easily removed from the base  16  by lifting these elements from the base. An electrical supply unit  18  as best shown in FIG. 4 is separate from the base  16  and the chimney  12  but is seated within the housings forming the base  16  and the chimney  12 . 
     The base  16 , as shown in FIGS. 1,  3 ,  4 , and  5   a , can be made as a one-piece molded plastic item having a bottom wall  16   a , a peripheral wall  16   b  following the configuration of the base  16 , a front compartment  16   c  for storing the electrical power supply  16   d , and a power supply wire  16   e . The floor  16   a  is molded to provide a seat for the boiling tray  26 , which will be described later, and to define an air plenum  28  defined between the bottom wall  16   a  and the boiling tray  26 . 
     A boiling tray  26  is seated within the base  16  and is easily removed therefrom. The boiling tray  26 , as shown in FIGS. 6 a  through  6   c , includes a central portion  27  in which the heating element  34  will be suspended The boiling tray  26  has a bottom wall  26   a  and a peripheral upstanding wall  26   b  which is continuous and follows the configuration of the boiling tray  26 . Air chimneys in the form of pipes  30  are defined around the central portion  27  located in the tray, and water channels  32  are designed in the tray to allow a longer path for the water coming from the reservoirs  14   a  and  14   b  to arrive in the area of the heating element  34 . This reduces the transfer of heat by means of the water to the reservoirs  14   a  and  14   b    
     As shown in FIGS. 3 and 4, the tray  26  is seated on the base  16  and defines an air plenum  28  between the bottom wall  26   a  of the tray  26  and the base  16 . Thus, when the tray  26  is seated on the base  16 , air will be drawn in through the air inlet opening  22  (FIG. 4) and then pass upwardly through the air pipes  30  into the chimney  12  to be mixed with the water vapor generated in the boiling tray  26 . 
     By heating the water in the boiling tray  26  close to boiling, the evaporation of the water will be accelerated as it is heated, and the vapors so formed will rise in the chimney  12  towards the outlet  24 . Without a fan, the hot water vapor rising in the chimney would increase the temperature of the surface of the chimney housing  12  to unbearable levels, making it too hot to touch. The provision of the pipes  30  in the boiling tray  26 , aligned with the chimney  12 , allows cooling air in the plenum  28  to rise with the vapors and cool off the vapors. Thus, the ambient temperature of the water vapor mixed with air coming out of the opening  24  is considerably reduced even without the use of a fan. 
     As shown in FIG. 3, the reservoirs are provided with valves  38  normally closing the water outlet  36 . When the reservoirs  14   a  and  14   b  are seated on the base  16 , the projection  40  of base  16  and the corresponding projection  41  of the tray  26  engage the plunger  38   a  against the spring to open the water outlet  36  to allow the water to flow into the tray  26 . 
     The chimney  12  is well illustrated in FIGS. 1 to  5   a.  It is an open-ended tubular member where the open end can sit on the base  16 . The tubular wall  12   a  defines the vapor chamber and is aligned vertically with the pipes  30  in the tray  26 . The rear portion of the chimney  12  defines an opening  22  which permits fresh ambient air to enter into the base  16  and utimately the plenum  28 . The front of the chimney  12  includes a cut-out window  22   a  exposing the electrical control panel  20 . 
     The electrical control panel  20 , on the electrical supply unit  18 , projects through an opening in the housing  13  of the chimney  12 . The housing  13  of the chimney  12  also defines an air inlet opening  22  in the rear side of the humidifier, as best shown in FIGS. 2 and 4. The housing of the chimney  12  defines an air outlet  24  at the very top thereof. 
     As can be seen from FIGS. 3 and 4, the water reservoirs  14   a  and  14   b  are easily removed from the base  16 . The chimney  12  can also be easily lifted from the base  16  exposing the electrical supply unit  18  and the tray  26 . Since the bottom of the chimney  12  is open, it can be easily cleaned. 
     The heating element  34  is electrically connected to the electrical supply unit  18  by means of connector  35 . A reset switch  48  on the end of a link arm  48   a,  as shown in FIG. 5 a,  can be provided to disconnect the corrent to the heating element  34 . 
     Referring now to FIGS. 5 a  to  5   c,  the electrical supply unit  18  includes a sealed housing  46 . A humidistat  44  is mounted within the housing  46  and is controlled by a control knob  42  mounted on the control panel  20 . FIG. 5 b  shows the sealed electrical connection which includes an electrical male connector  52  in the base  16  and a female electrical socket  54  formed in the housing  46  of the electrical supply unit  18 . Thus, the electrical supply unit  18  can be removed from the base  16  using a conventional prong and socket connection. 
     A microswitch  50  may be provided to disconnect the electrical current when the chimney  12  is removed from the unit. 
     A reset button  56  is provided on the control panel  20 . 
     Thus, in summary, the various elements forming the humidifier  10  are modular and can all be removed allowing proper cleaning. The chimney  12  is easily lifted from the base  16  as are the water reservoirs  14   a  and  14   b . In fact for filling purposes the reservoirs  14   a  and  14   b  can be individually removed without affecting the operation of the humidifier. The electrical supply unit  18  can then be removed once the chimney  12  is removed and the heating element  34  connected to the electrical unit will be lifted from the boiling tray  26 . Finally the boiling tray  26  can be easily lifted out of the base  16  for purposes of cleaning both the boiling tray  26  and the interior of the base  16 . 
     The elements may be reassembled in reverse order. 
     As shown in FIG. 3, the reservoirs are provided with valves  38  normally closing the water outlet  36 . When the reservoirs  14   a  or  14   b  are seated on the base  16 , the projection  40  of the base  16  and the corresponding projection  41  of the tray  26  engage the plunger  38   a  against the spring to open the water outlet  36  to allow the water to flow into the tray  26 . 
     The chimney  12  is well illustrated in FIGS. 1 to  5   a.  It is an open-ended tubular member where the open end can sit on the base  16 . The tubular wall  12   a  defines the vapor chamber and is aligned vertically with the pipes  30  in the tray  26 . The rear portion of the chimney  12  defines an opening  22  which permits fresh ambient air to enter into the base  16  and ultimately the plenum  28 . The front of the chimney  12  includes a cut-out window  22   a  exposing the electrical control panel  20 . 
     The electrical control panel  20 , on the electrical supply unit  18 , projects through an opening in the housing  13  of the chimney  12 . The housing  13  of the chimney  12  also defines an air inlet opening  22  in the rear side of the humidifier, as best shown in FIGS. 2 and 4. The housing of the chimney  12  defines an air outlet  24  at the very top thereof. 
     As can be seen from FIGS. 3 and 4, the water reservoirs  14   a  and  14   b  are easily removed from tile base  16 . The chimney  12  can also be easily lifted from the base  16  exposing the electrical supply unit  18  and the tray  26 . Since the bottom of the chimney  12  is open, it can be easily cleaned. 
     The heating element  34  is electrically connected to the electrical supply unit  18  by means of connector  35 . A reset switch  48  on the end of a link arm  48   a,  as shown in FIG. 5 a,  can be provided to disconnect the current to the heating element  34 . 
     Referring now to FIGS. 5 a  to  5   c,  the electrical supply unit  18  includes a sealed housing  46 . A humidistat  44  is mounted within the housing  46  and is controlled by a control knob  42  mounted on the control panel  20 . FIG. 5 b  shows the sealed electrical connection which includes an electrical male connector  52  in the base  16  and a female electrical socket  54  formed in the housing  46  of the electrical supply unit  18  Thus, the electrical supply unit  18  can be removed from the base  16  using a conventional prong and socket connection. 
     A microswitch  50  may be provided to disconnect the electrical current when the chimney  12  is removed from the unit.