Patent Publication Number: US-10781551-B2

Title: Steam iron

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Chinese Patent Application No. 201721673926.2, filed on Dec. 5, 2017. 
     FIELD 
     The disclosure relates to a steam iron, and more particularly to a steam iron with adjustable steam output. 
     BACKGROUND 
     Referring to  FIG. 1 , a conventional steam iron includes a machine body unit  11 , a sole plate unit  12  connected to a bottom end of the machine body unit  11 , a water tank unit  13  mounted in the machine body unit  11 , a steam unit  14 , and a control unit  15 . 
     The sole plate unit  12  includes a sole plate  122  that is adapted for ironing a piece of cloth and that is formed with a plurality of steam holes  121  in fluid communication with the external environment, and a first heating member  123  that is for heating the sole plate  122 . The water tank unit  13  includes a water chamber  131  for storing liquid water, a second heating member  132  for heating the liquid water in the water chamber  131 , and a water inlet  133  that interconnects the water chamber  131  and the steam unit  14  for transporting the liquid water in the water chamber  131  to the steam unit  14 . The steam unit  14  includes a steam chamber  141  that is connected to the water inlet  133  for receiving the liquid water therefrom, a third heating member  142  for evaporating the liquid water into steam by heating, and a steam valve  143  that fluidly communicates the steam chamber  141  and the sole plate  122 . The control unit  15  includes a microcontroller  151 , and a gyroscope  152  that is electrically connected to the microcontroller  151 . 
     The microcontroller  151  opens or closes the steam valve  143  based off orientation measurement of the conventional steam iron measured and transmitted by the gyroscope  152 . For example, when the conventional steam iron is placed in a vertical position, the gyroscope  152  signals the microcontroller  151  to close the steam valve  143 , ensuring that the steam in the steam chamber  141  cannot enter the sole plate  122 . When the conventional steam iron is placed from the vertical position to a horizontal position, the steam valve  143  is signaled to open, allowing the steam from the steam chamber  141  to pass therethrough for ironing the piece of cloth. 
     While the abovementioned steam iron is able to open or close the steam valve  143  based off the orientation of the steam iron, it is not capable of controlling the intensity of the steam applied onto the piece of cloth. The design of the heating members  123 ,  132 ,  142  also complicates the algorithms needed for the microcontroller  151  to control them simultaneously. 
     SUMMARY 
     Therefore, an object of the disclosure is to provide a steam iron that can alleviate the drawback of the prior art. 
     According to the disclosure, the steam iron is adapted for ironing a piece of cloth with steam generated thereby. The steam iron includes a machine body unit, a sole plate unit, a water supply unit, a heating unit, and a control unit. The sole plate unit is connected to a bottom end of the machine unit. The water supply unit is connected to the machine body unit and includes a pump that is adapted for supplying water to the sole plate unit. The heating unit is connected to the sole plate unit and heats up the sole plate unit so that the water supplied to the sole plate unit is heated to form the steam. The control unit is connected to the machine body unit, measures moving speed of the steam iron and controls water output of the pump based on the moving speed of the steam iron. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment with reference to the accompanying drawings, of which: 
         FIG. 1  is a schematic view of a conventional steam iron; 
         FIG. 2  is an exploded perspective view of an embodiment of a steam iron according to the disclosure; 
         FIG. 3  is a sectional side view of the embodiment; and 
         FIG. 4  is a sectional view taken along line IV-IV in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 2 to 4 , an embodiment of a steam iron according to the disclosure is adapted for ironing a piece of cloth with steam generated thereby, and includes a machine body unit  4 , a sole plate unit  2  that is connected to a bottom end of the machine body unit  4 , a heating unit  3  that is connected to the sole plate unit  2 , a water supply unit  5  that is connected to the machine body unit  4 , and a control unit  6  that is connected to the machine body  4 . 
     The sole plate unit  2  includes a hot plate  21 , abase plate  22 , and an ironing plate  23 . The hot plate  21  has a plate wall  211  and two spaced apart outer and inner surrounding walls  212 ,  212 ′ that extend upward from a peripheral portion of the plate wall  211 . The plate wall  211  has a pointy front end and a wider rear end, and is formed with an upward protrusion  213  that is surrounded by the inner surrounding wall  212 ′ and a plurality of through holes (not shown) that are disposed between the outer and inner surrounding walls  212 ,  212 ′. The base plate  22  is disposed below the machine body unit  4  and on top of the hot plate  21 , and cooperates with the hot plate  21  to define a heating chamber  24  that is in fluid communication with the through holes. The ironing plate  23  is mounted at a bottom end of and in thermal contact with the hot plate  21  (i.e., the hot plate  21  is disposed between the machine body unit  4  and the ironing plate  23 ), is adapted for ironing the piece of cloth, and cooperates with the ironing plate  23  to define a spacing chamber  25  therebetween. The spacing chamber  25  acts as a temperature buffer between the hot plate  21  and the ironing plate  23 , reducing the rate of temperature change of the ironing plate  23 . The ironing plate  23  is formed with a plurality of steam holes  231  that are fluidly communicated with the spacing chamber  25  for applying the steam onto the piece of cloth. 
     The heating unit  3  includes a heating member  31  that is mounted in the hot plate  21  of the sole plate unit  2 , and a temperature control member  32  that is mounted on the base plate  22  of the sole plate unit  2  and that is electrically connected to the heating member  31  for controlling temperatures of the heating member  31  and thus the hot plate  21 . 
     The machine body unit  4  includes a base seat  41  that houses the water supply unit  5 , a casing  42  that is mounted on the base seat  41 , and a handle cover  43  that is mounted on the casing  42 . The casing  42  has an inverted U-shaped handle portion  421  for a user to grip thereon and a case body portion  422  that covers the base seat  41 . A top portion of the handle portion  421  is formed with a mounting groove  423  that can fit the control unit  6  therein. The case body portion  422  and the handle portion  421  cooperatively define handle space  44  for the user to extend his or her fingers therethrough, and the case body portion  422  and the base seat  41  cooperatively define a water tank chamber  45 . The handle cover  43  is mounted to the handle portion  421  for sealing the mounting groove  423 . 
     The water supply unit  5  includes a pump  51  that is mounted to the base seat  41  of the machine body unit  4 , a pumping tube  52  that is fluidly connected to the water tank chamber  45 , and a water-supplying tube  53  that extends through the base seat  41  to be in fluid communication with the heating chamber  24  of the sole plate unit  2 , and that is adapted for supplying water to the hot plate  21  of the sole plate unit  2 , in which the heating member  31  of the heating unit  3  heats up the hot plate  21  so that the water supplied to the hot plate  21  is heated to form the steam. Unless otherwise stated, water is assumed to be in liquid form and in room temperature. 
     The control unit  6  is mounted in the mounting groove  423  of the casing  42  of the machine body unit  4 , and includes a three-axis accelerometer  61 , a switch member  62  that is operable to turn on or off the three-axis accelerometer  61 , a control circuit  63  that is electrically connected to the three-axis accelerometer  61  and the pump  51  of the water supply unit  5 , and an air spray switch  64  that is electrically connected to the control circuit  63 . In this embodiment, the three-axis accelerometer  61  is an ADXL 345 accelerometer, capable of measuring acceleration in a three-dimensional space within the range of 19.6 m/s 2  at 10-bit measurement. The switch member  62  is operable to turn off the three-axis accelerometer  61  when the user desires to dry iron, and therefore trigger the control circuit  63  to stop operation of the pump  51 . 
     During operation of the steam iron of this disclosure, the pump  51  draws the water from the water tank chamber  45  through the pumping tube  52 , and pump the water into the heating chamber  24  through the water-supplying tube  53 . When the water is in direct contact with the protrusion  213  of the hot plate  21  in the heating chamber  24 , as the hot plate  21  is heated by the heating member  31 , the water evaporates into the steam, moves to the spacing chamber  25  through the through holes, and then leaves the spacing chamber  25  through the steam holes  231  to be in contact with the piece of cloth. 
     The three-axis accelerometer  61  measures acceleration of the steam iron and transmits a measured signal to the control circuit  63 . The control circuit  63  transmits a control signal to the pump  51  based on the measured signal, such that the pump  51  supplies a corresponding amount of the water to the hot plate  21  of the sole plate unit  2  based on the control signal. 
     In this embodiment, the control unit  6  reduces the amount of the water supplied by the pump  51  (and consequently the amount of the steam generated) when the user swiftly irons a specific section of the piece of cloth. As swift movement from the user may suggest that presence of the crease on the piece of the cloth is minimal, the steam output is reduced accordingly. On the other hand, the control unit  6  increases the amount of the steam generated, by increasing the amount of the water supplied by the pump  51 , when the user irons slowly, as such movement may suggest great presence of crease on the piece of cloth. 
     Specifically, in this embodiment, the control unit  6  controls the output of the steam based off the following programmed logistics: 
     1) The three-axis accelerometer  61  has a minimum detectable acceleration value. In this embodiment, the minimum detectable acceleration value is (19.6÷1024) m/s 2 , or 0.01914 m/s 2 . The three-axis accelerometer  61  continuously measures the acceleration of the steam iron every 50 milliseconds (ms) throughout the operation of the steam iron. For every ninety consecutive measurements of the acceleration, the control unit  6  compares the measured value with 9 times the minimum detectable acceleration value (or 0.17227 m/s 2  in this embodiment). When the measured value is less than 9 times the minimum detectable acceleration value in more than seventy-nine measurements out of the ninety measurements, the three-axis accelerometer  61  transmits the measured signal to the control circuit  63  to stop the pump  51  from supplying the water to the hot plate  21 . 
     2) The steam iron has a maximum steam output, denoted M. The control circuit  63  is configured to control steam output of the steam iron to be (1/N)*M where N ranges from 1 to 7. The three-axis accelerometer  61  continuously measures the acceleration of the steam iron every 50 ms, and compares each measured value of acceleration of the steam iron with a previous measured value of acceleration of the steam iron 50 ms ago. The three-axis accelerometer  61  transmits the measured signal to the control circuit  63  to control the pump  51  such that the steam iron decreases the steam output thereof when the difference between the measured value of acceleration of steam iron with the previous measured value of acceleration of the steam iron is greater than 50 times the minimum detectable acceleration value (or 0.95703 m/s 2  in this embodiment). On the other hand, the three-axis accelerometer  61  transmits the measured signal to the control circuit  63  to control the pump  51  such that the steam iron increases the steam output thereof when the difference between the measured value of acceleration of steam iron with the previous measured value of acceleration of the steam iron is smaller than 50 times the minimum detectable acceleration value. 
     3) The steam output of the steam iron is initially set to be (1/N)*M where N equals to 3. In each comparison, N increases by 1 when the difference between the measured value of acceleration with the previous measured acceleration of the steam iron is greater than 50 times the minimum detectable acceleration value, and N decreases by 1 when the difference between the measured value of acceleration with the previous measured value of acceleration is smaller than 50 times the minimum detectable acceleration value. 
     In actual use, instead of relying on the control unit  6  for monitoring the steam output, the user may operate the air spray switch  64  to control the control circuit  63  to manually increase the amount of the water supplied to the hot plate  21  by the pump  51 , such that steam output of the steam iron is increased. 
     Overall, by directly adding the water to the hot plate  21  to generate steam, the steam iron of this disclosure does not need a dedicated steam chamber or multiple heating members. The control circuit  63  transmits a control signal to the pump  51  based on the measured signal from the three-axis accelerometer  61 , such that the pump  51  supplies a corresponding amount of the water to the hot plate  21  of the sole plate unit  2  based on the control signal. 
     In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects, and that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure. 
     While the disclosure has been described in connection with what is considered the exemplary embodiment, it is understood that this disclosure is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.