Patent Publication Number: US-2002000365-A1

Title: Water distiller

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a water distiller, and more particularly to an arrangement in the bottom wall of a container and a push button of a thermostat of the water distiller.  
       [0003] 2. Description of the Related Art  
       [0004] U.S. Pat. No. 4,342,623 to Loeffler issued on Aug. 3, 1982 discloses a portable water distiller that includes a container and a cover mounted on top of the container. A sealing gasket is provided in the cover to be in contact with cylindrical wall of the container. The cover further includes air inlet and air outlet so as to allow air convection to the condenser coil and the fan. A tube conveys the steam from the container to the condenser coil. A heater is directly mounted to the bottom wall of the container in a manner that the thermostat opens in response to a sudden rise in the temperature of the container and the heating plate after the raw water in the container has been boiled to exhaustion. However, a conductive silicon layer applied between the heating plate of the heater and the container may malfunction as a result of overheating while the heating plate tends to deform at high temperature. Thus, the thermostat malfunctions easily, and scale tends to accumulate on the inner periphery of the container as a result of excessive heat.  
       [0005] The present invention is intended to provide an improved water distiller that mitigates and/or obviates the above problems.  
       SUMMARY OF THE INVENTION  
       [0006] It is a primary object of the present invention to provide a water distiller with a bottom wall configured to avoid overheating of the container and the heating plate.  
       [0007] It is a secondary object of the present invention to provide a water distiller, wherein a spring is provided to reliably bias the thermostat to be in an intimate contact with a cylindrical wall of the container, thereby improving the contact between the thermostat and a thermal conductive plate of the container.  
       [0008] A water distiller in accordance with the present invention comprises a shell, a container, a heater, a thermal conductive plate, a thermostat, a cover, a condenser coil, and a fan. The shell provides a compartment for receiving the container, the heater, the thermal conductive plate, and the thermostat. The container includes a bottom wall with an inclined surface to which the heater is connected. A higher end of the inclined surface is connected to the thermal conductive plate and the thermostat. The thermostat is mounted in a room provided between the shell and the container, and a first spring is provided to bias the thermostat to be in an intimate contact with cylindrical side wall of the container. A cap is mounted outside the room and a push button is mounted in the cap with an end exposed outside the cap for manual operation. A second spring is mounted in the cap for biasing the push button to a position for the manual operation. The cover provides a compartment for receiving the condenser coil and the fan. The cover is mounted on top of the shell such that the shell and the cover together form an enclosed container. The container receives raw water which is vaporized by the heater, and the steam condenses by the condenser coil and the fan.  
       [0009] The overheating problem of the conventional water distiller is avoided in the water distiller of the present invention by means of provision of the inclined surface in the bottom wall of the container such that a pre-determined control temperature is reached and the power is shut off before the raw water in the container is boiled to exhaustion. Thus, overheating of the container and the thermal conductive plate is avoided. In addition, poor contact between the container and the thermostat is avoided by means of providing a spring to bias the thermostat toward the container.  
       [0010] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011]FIG. 1 is a longitudinal sectional view of a water distiller in accordance with the present invention;  
     [0012]FIG. 2 is an enlarged sectional view of an upper portion of the water distiller in accordance with the present invention;  
     [0013]FIG. 3 is an enlarged sectional view of a lower portion of the water distiller in accordance with the present invention, wherein the raw water in the container nearly boils to exhaustion; and  
     [0014]FIG. 4 is an enlarged view of a circle in FIG. 3. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0015] Referring to FIGS. 1 through 3, a water distiller in accordance with the present invention generally includes a shell  10 , a container  11 , a heater  12 , a thermostat  13 , a cover  14 , a condenser coil  15 , and a fan  16 . The shell  10  includes a compartment for receiving the container  11 , the heater  12 , a thermal conductive plate  122 , and the thermostat  13 . The container  11  includes a bottom wall with an inclined surface  111  to which the heater  12  is connected. The thermostat  13  is mounted to a cylindrical side wall of the container  11  at a portion adjacent to the higher end of the inclined surface  111 .  
     [0016] A push button  131  is operably connected to the thermostat  13  to turn on or turn off the water distiller. Referring to FIG. 4, the thermostat  13  is mounted in a room  132  outside the container  11 . A first spring  133  is attached between an end wall  136  of the room  132  and the thermostat  13 . A cap  135  is mounted outside the room  132  and defines a chamber  137  for receiving a second spring  134  that is attached between the end wall  136  of the room  132  and an enlarged head  138  of the push button  131 . The second spring  134  is provided for returning the push button  131  to a position for user&#39;s push. The first spring  133  biases the thermostat  13  to be in reliable intimate contact with the cylindrical side wall of the container  11 .  
     [0017] Referring to FIGS. 1 and 2, the cover  14  provides a compartment for receiving the condenser coil  15  and the fan  16 . The condenser coil  15  is wound around the fan  16 . The cover  15  further includes an air inlet  141 , an air outlet  142 , and a water outlet  143 . Air is drawn into the cover  14  via the air inlet  141  and passes through the condenser coil  15  before it exits via the air outlet  142 . Steam generated by means of boiling raw water in the container  11  enters a steam inlet pipe  151  in an end of the condenser coil  15  and exits via the water outlet  143  after passing through a water discharge tube  152  in the other end of the condenser coil  15 . The cover  14  is mounted on top of the shell  10  such that the shell  10  and the cover  14  together form an enclosed container.  
     [0018] The container  11  receives raw water which becomes steam after being heated by the heater  12 . The steam in the container  11  enters the steam inlet pipe  151  of the condenser coil  15  in the cover  14  and then condenses into distilled water as a result of temperature reduction by the condenser coil  15  and the fan  16 . The distilled water flows out of the water distiller via the water outlet  143 . When the container  11  is filled with raw water, the heater  12  heats and thus vaporizes the raw water until the thermostat  13  shuts off the power under a condition that the temperature of the container reaches a pre-determined value.  
     [0019] Referring to FIG. 3, when the level of the raw water in the container  11  is lowered to expose the higher end of the inclined surface  111  of the bottom wall of the container  11 , the heater  20  still heats the raw water above the lower end of the inclined surface  111 , yet the higher end of the inclined surface  111  has a higher rise in the temperature than the lower end of the inclined surface  111 , and the heat is conducted to the thermostat  13 . The thermostat  13  shuts off the power when it reaches a pre-determined temperature to avoid overheating to the bottom wall of the container  11  that might damage the heater  12  and the container  11 . Accordingly, the water distiller in accordance with the present invention avoids the overheating problem encountered in the water distiller of U.S. Pat. No. 4,342,623.  
     [0020] A comparison table 1 is listed as follows to indicate differences between the water distiller (“The invention”) in accordance with the present invention and a conventional water distiller (“Prior art”) under the same input power of 800 W.  
                           TABLE 1                                      Normal Working Status   Stop Heating Status                                     temperature   temperature   temperature   temperature           of thermostat   of heater   of thermostat   of heater                                             Prior art   100° C.   160° C.   117° C.   230° C.       The invention   100° C.   160° C.   117° C.   180° C.                  
 
     [0021] The water distiller in accordance with the present invention has an inclined surface in a bottom wall of the container, yet the conventional water distiller has no such arrangement. It is apparent from the above table that the temperatures of the heaters in both water distillers are identical. Nevertheless, when the thermostat reaches a pre-determined temperature of 117° C., the temperature of the heater of the invention is lower than that of the heater of the prior art by 50° C. The container will be seriously damaged as a result of overheating when the temperature of the heater exceeds beyond 200° C. Accordingly, in the conventional water distiller, the conductive silicon layer applied between the heating plate of the heater and the container malfunctions, the heating plate tends to deform, and operation of the thermostat is not satisfactory.  
     [0022] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.