DESCRIPTION OF THE PREFFERED EMBODIMENTS

[0013] Wherever possible in the following description, like reference numerals will refer to like elements and parts unless otherwise illustrated.

[0014] Referring to FIG. 1 through FIG. 4, various schematic views illustrate a steam-cleaning appliance according to an embodiment of the invention. The steam-cleaning appliance principally comprises a housing 10 in which is mounted a steam device 30. Via the steam device 30 the flow and the amount of steam generated is controlled in the steam-cleaning appliance.

[0015] A water storage chamber 11 is mounted onto the housing 10 to receive cold water. The water storage chamber 11 may be formed with the housing 10 into one single body by, for example, stamping. A removable cover 12 is further mounted onto the water storage chamber 11 to allow the user to refill water therein. Within the housing 10, a pump 20 is arranged on a positioning support 13 to pump cold water from the water storage chamber 11 via a pipe 5a.

[0016] The steam device 30 comprises a water-flowing path 31 and a heating unit 32 placed vis-a-vis the water flowing path 31 (the heating unit 32 is an electro-heating pipe). A water inlet 311 of the water-flowing path 31 is connected to the pump 20 via a pipe 5b. A water outlet 312 of the water-flowing path 31 is connected to the output of a nozzle 40 via a steam pipe 5c to deliver steam formed by heating of the cold water in the water-flowing path 31 by means of the heating unit 32. The water-flowing path 31 and the heating unit 32 are U-shaped, and are mounted onto each other according to an opposite superposition. A temperature sensor 33 is arranged at the location of the water inlet 311 to control the turn on/off of the heating unit 32.

[0017] When the user wants to use the steam-cleaning appliance, he or she first turns on a principal switch 14, externally placed on the housing 10 that controls the general electrical connection of the steam-cleaning appliance to a power supply. While holding the nozzle 40 toward the object to be cleaned, the user can switch a multi-state controller 41 on the nozzle 40 into various configurations to control steam output delivered by the pump 20. Continuous, intermittent, or stop configuration hence can be selected to control the steam output. Other controllers, for controlling for example the amount and flow of steam output, may be also available to let the user more functionality to control the steam output. Once the controller 41 turns on the pump 20, the pump 20 pumps cold water from the water storage chamber 11. Cold water then passes through the pipes 5a, 5b to enter the water inlet 311 of the water-flowing path 31. The passage of cold water through the water inlet 311 is sensed via the temperature sensor 33 (the temperature sensor 33 is activated via a turn on of the principal switch 14 to sense the temperature of the water inlet 311). The temperature sensor 33 then outputs a signal that commands the activation of the heating unit 32 to heat cold water.

[0018] FIG. 2 illustrates an example of electrical connection to implement the above mechanism, in which the electrical terminals of both principal switch 14 and heating unit 32 are respectively connected to the electrical terminals of the temperature sensor 33. The electrical connection of the different electrical terminals depends on the control relationship between the devices, which is known in the art and, therefore, omitted in this description.

[0019] Because both water-flowing path 31 and heating unit 32 are U-shaped and placed in opposite superposition, cold water starts to be heated once passing through the water inlet 311 to penetrate into the water-flowing path 31. While flowing through the water-flowing path 31, water is thereby continuously heated until being sputtered into steam via the water outlet 312. The steam is transferred to the nozzle 40 via the steam pipe 5c to be finally sputtered onto the object to be cleaned. Therefore, the user does not need to wait for the formation of steam by heating, and can efficiently control the amount of steam adapted to the cleaning of the object.

[0020] To prevent excessive external heating of the housing 10 and internal damages due to high heating temperature, the steam device 30 further includes a casing 34 that is externally covered with a thermal isolation element 35 (such as asbestos) and encloses the water-flowing path 31 and the heating unit 32. Additionally, a positioning pedestal 15 is arranged into the housing 10 to up set the steam device 30 and, thereby, maintain a distance between the steam device 30 and the housing 10. Heat generated by the heating unit 32 thus does not affect the housing 10. Moreover, the temperature sensor 33, controlling the turn on/off of the heating unit 32, is placed at the location of the steam device 30 that is subjected to the lowest temperature, which is the water inlet 311 of the water-flowing path 31. As a result, the steam temperature can be controlled within a desired range, and a safe use can be thereby ensured.

[0021] It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the invention. The invention should therefore cover various modifications and variations made to the herein-described structure and operations of the invention, provided they fall within the scope of the invention as defined in the following appended claims.