DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows a perspective view of a steam-sterilizing vacuum cleaner according to a preferred embodiment of the present invention. The present steam-sterilizing vacuum cleaner can be constructed, by combining at least part of components of conventional vacuum cleaner (such as, vacuum-type dust suction unit, vacuum cleaner body, etc) with a steam-generating unit for generating steam by chemical reaction and steam spray unit of the present invention.

[0017] In the FIG. 1, the steam-generating unit is preferably installed inside of the vacuum cleaner body 30 for the purpose of attractive external appearance of the cleaner, and it is obvious to those skilled in the art that such a construction would not limit the scope of the invention. Therefore, it is also possible to construct variations of the vacuum cleaner by extending all or part of the components of the steam-generating unit beyond the outer surface of the vacuum cleaner body 30. For the purpose of attractive external appearance, the vacuum cleaner body 30 designed as shown in the FIG. 1 has preferably one frame formed with a base, sides, and a part of a top surface, while the other part of the top surface is preferably formed with a cover 33 (or lid) capable of being opened.

[0018] The vacuum cleaner body 30 has a discharge opening 60 formed on one side thereof for discharging air after purification, and a liquid (specifically, water) inlet 23 and a water tank switch S for turning on and off the supply of electric power into the steam spray unit formed on a part of the top surface. In addition, the vacuum cleaner body 30 includes a suction opening 34 through which a suction hose 31 of a suction unit which sucks air including dust is connected to a dust-collecting room 32, and a steam outlet 24 for discharging the steam generated from the steam-generating unit to an exterior steam spray unit, formed on a front side thereof.

[0019] The suction unit comprises a suction plate 50, a suction hose 31 for connecting the suction plate 50 with a suction opening 34, and an operation switch 35. The suction hose 31 is connected to the suction opening 34 with a coupling. And, the steam spray unit comprises a steam spray plate 51, and a steam discharge hose 26 for connecting the steam spray plate 51 with the steam outlet 24, as shown in FIG. 1. While, the steam discharge hose 26 is connected to the steam outlet 24 with a coupling, and the steam spray plate 51 of the steam spray unit is formed in the same shape but a little bit smaller than the suction plate 50 of the suction unit so as to be attachable to and detachable from spray plate holders 52 formed on both front sides of the suction plate 50. Accordingly, the vacuum cleaner of the present invention has a simple structure over the conventional one, the steam sprayed therefrom is sprayed more evenly to an object to be sterilized. The present vacuum cleaner also has attractive appearance and is convenient to use.

[0020] Next, an interior structure of the vacuum cleaner body will be described in detail, with reference to the FIG. 2 and 3. The components inside the vacuum cleaner body include a steam-generating unit comprising a water tanker 20, carbon plates 21 and 21′ and a partition 22, a water inlet 23, a steam outlet 24, a dust-collecting room 32, and a filtering net 42 through which purified air is passed and discharged. The dust-collecting room 32 is a place where the dust from the object to be cleaned is collected through the suction plate 50, suction hose 31 and suction opening 34 of the suction unit with a vacuum-generating unit electrically connected to the operation switch 35. The dust collected in the dust-collecting room 32 is generally filtered through the filtering net 42 (or, dust-collecting net) and discharged through the discharge opening 60, by the operation of a motor 40 and a fan 41 electrically connected to the operation switch 35.

[0021] In the meanwhile, the vacuum-generating unit for sucking dust from an object to be cleaned and/or the air discharge unit are known generally, and it is easily possible for those skilled in the art to realize such embodiments, accordingly, the detailed description thereof will not described further.

[0022] According to an embodiment of the invention, a steam-generating unit provided at the front of the inside of the vacuum cleaner body 30 comprises a water tank 20 supported inside the vacuum cleaner body for keeping an electrolytic solution therein; a water inlet 23 extended from the water tank 20 into and beyond the top surface of the vacuum cleaner body 30; at least two carbon plates 21 and 21′ spaced apart each other which are supported by the water tank 20 and to which electric current can be applied; an electrically non-conductible partition 22 provided at a median position between the carbon plates 21 and 21′ with the same area as the carbon plates; and a steam outlet 24 for discharging steam generated from the inside of the water tank 20 to the steam discharge hose 26 of exterior steam spray unit. The suction opening 34 shown in FIGS. 1 and 2 is provided beneath the water tank 20 as shown in the FIG. 3, so as to be connected with the dust-collecting room 32 shown in FIG. 2.

[0023] The steam-generating unit of aforementioned construction generates steam by chemical reaction, and operation principle thereof is as follows. First, weak electric current is applied to two carbon plates 21 and 21′ with separate positive and negative electrodes. Then a chemical reaction takes place at an interface between saline water, which is a preferred example of the electrolytic solution, and two carbon plates 21 and 21′. As a result of such chemical reaction, water vapor of high temperature and high pressure and oxygen are generated and mixed together into steam. The steam generated by such a process is supplied to the steam discharge hose 26 and the steam spray plate 51, which constitute the steam spray unit, through the steam outlet 24. At this time, pure water and carbon plates 21 and 21′ to which weak electric current is applied do not lead to any chemical reaction. However, if a certain amount of salt (sodium chloride), which is a kind of basic substance such as calcium chloride and potassium chloride, is dissolved in water, the saline water becomes electrically conductible (it is not preferable to dissolve too much salt in water because too much salt causes intensive chemical reaction between the saline water and the carbon plates). Accordingly, a chemical reaction takes place between the carbon plates 21 and 21′ and the saline water through which weak electric current is flowing so as to generate heat and resulting steam.

[0024] An electrically non-conductible partition 22 is provided in order to prevent a direct chemical reaction between the two carbon plates 21 and 21′, and therefore it is preferable to install the partition 22 so that the partition 22 cannot seal the entire space between the carbon plates 21 and 21′. The water vapor generated from the chemical reaction between the saline water and the carbon plates 21 and 21′ is of high temperature (commonly, about 120 to 130° C.) because the saline water which is an electrolytic solution has high boiling point. In addition, the high density of water molecule contacting the large area of the carbon plates 21 and 21′ causes to increase the amount of water vapor generated per unit time, which in turn creates steam of high pressure.

[0025] In addition, it is possible to use small amount of salt once dissolved in the water continuously because the salt dissolved in the water does not evaporate by such a chemical reaction. Therefore, only water is need to be fed through the water inlet 23 when the amount of the electrolytic solution in water tank 20 is decreased due to the generation of steam. Furthermore, oxygen is also generated by the electrolysis when the chemical reaction between the saline water and the carbon plates 21 and 21′ takes place and is mixed into the water vapor. It has proven that the steam of high temperature and high pressure including such oxygen is more effective on sterilization and insect-killing over the pure water vapor, by experimental results of the present inventor. In addition, though the electric current applied to the carbon plates 21 and 21′ of the steam-generating unit of the invention is preferably weak alternating current (AC), it is possible to use direct current from batteries.

[0026] Now, the operation of the steam-sterilizing vacuum cleaner according to the present invention of the constructions shown in the FIG. 1 to 3 will be described in detail. First, a user turns on the operation switch 35 provided at the suction hose 31 while directing the suction plate 50 of the suction unit toward an object to be cleaned. Then, a vacuum-generating unit is driven and accordingly vacuum is created inside the dust-collecting room 32, which in turn generates suction effect so as to suck air including dust from the object to be cleaned.

[0027] While, if the user turns on the water tank switch S provided on the top surface of the vacuum cleaner body 30, weak electric current is supplied to the carbon plates 21 and 21′ of the steam-generating unit. Then, water vapor of high temperature and high pressure and oxygen are generated at the interface between the carbon plates 21 and 21′ and the saline water and mixed each other. This mixed steam passed through the steam outlet 24, the steam discharge hose 26 and the steam spray plate 51 and sprayed to the object to be cleaned. Therefore, the sterilization and insect-killing effect on the object to be cleaned is significantly increased by such sprayed steam of high temperature and high pressure.

[0028] Especially, a chemical reaction is used for generating steam in the steam-sterilizing vacuum cleaner of the present invention, so that electric power supplied to the steam-generating unit is automatically cut off when the water in the steam-generating unit is entirely evaporated. Accordingly, the present vacuum cleaner doesn't have to include additionally a safety device, a guage and manometer for cutting off electric power as in the conventional steam vacuum cleaner including an electric heater as a heating unit. Therefore, it is possible to lower the cost of the products by reducing the number of components, while keeping safer state in use over the prior art. In addition, the present vacuum cleaner has attractive appearance because it is not necessary to include such components at an exterior part of the vacuum cleaner. Furthermore, the conventional steam vacuum cleaner of heating type needs about 20 to 30 minutes to heat water and generate steam, however, it is proven in the experiment that the present steam-sterilizing vacuum cleaner can generate steam of high temperature and high pressure within 1 minute and accordingly it is very convenient to use. The present steam-sterilizing vacuum cleaner also has the advantage of very low power consumption due to the use of weak electric current. Moreover, the present steam-sterilizing vacuum cleaner generates oxygen in addition to the steam of high temperature and high pressure, which improves significantly the sterilization and insect-killing effect over the conventional one. The present vacuum cleaner has an additional advantage of convenience in use by forming the spray unit efficiently detachable to the suction unit.

[0029] In the meanwhile, it is also possible to incorporate an air purification and discharge unit according to the present invention into the above-described preferred embodiment of the invention. More specifically, the air purification and discharge unit(not shown) comprises a vessel supported by the body for keeping a solution (preferably, water) therein inside the duct-collecting room 32 instead of the filtering net 42 (or dust-collecting net) shown in FIG. 2. Then, a proper amount of water (about two thirds or three fourths of the vessel) is filled the vessel, a sponge is provided properly on the top surface of the solution, a second hose is extended from the dust-collecting room 32 above the vessel to the bottom of the vessel (in the water), and a third hose connected to the air outlet is disposed in the layer of air above the sponge in the vessel. The air purification and discharge unit sucks dust into the water in the vessel, filters every tiny dust by the water and discharges only purified air to the outside of the body, when the dust is sucked into the dust-collecting room 32 by the operation of the vacuum cleaner. This has great air purification effect over the conventional filter-using air purification system. When adopting such an air purification and discharge unit into the vacuum cleaner body, it is not necessary to use the filtering net 42 shown in the FIG. 2.

[0030] In another variation, it is possible to compensate possible temperature loss during the passage through the steam discharge hose 26 so as to spray steam of higher temperature and high pressure, by incorporating additional heater including a safety device near the steam spray plate 51.

[0031] In yet another variation, the operation switch 35 of the suction unit is provided at the suction hose unit and the water tank switch S is provided at the top surface of the vacuum cleaner body, respectively. However, it also is possible to provide both switches at proper positions of the suction hose 31, respectively, so as to improve convenience in use. It is yet possible to combining electrically the two switches into one switch so that the suction unit and the spray unit can be operated at the same time. In still another variation, the present vacuum cleaner can have at least two steam-generating units including carbon plates 21 and 21′ so that the steam generated from the steam-generating units can be converged into the steam outlet 24, and it is obvious that such variations fall within the scope of the present invention.

[0032] It is also obvious that the present steam-sterilizing vacuum cleaner can be used as a domestic steam-sterilizing vacuum cleaner and/or an industrial one within the scope of the present invention, by varying the size and capacity of the vacuum cleaner having above-described constructions, and accordingly the detailed description thereof will not be made further.

[0033] Other variations that can be made within the scope of the present invention described above are as follows.

[0034] FIGS. 4 to 6 are a perspective view, a side section view, and a front section view of a vacuum cleaner suction unit according to another embodiment of the present invention, respectively. As shown in the FIGS. 4 to 6, there is provided a water tank including a water inlet formed thereon for keeping water inside the body of the suction unit, and a steam vessel disposed at a bottom of the water tank for generating steam.

[0035] Carbon plates 91, 91′, 91″ and 91′″ connected with an electric cord 61 and electrically non-conductible partitions 92, 92′ and 92″ having the same area as the carbon plates located between each two carbon plates are provided inside the steam vessel 80. And, it is preferable to use saline water as the electrolytic solution for generating steam by chemical reaction. There is provided a steam spray nozzle 81 for spraying the steam in high pressure when a certain level of pressure is created inside the steam vessel 80.

[0036] The water tank 70 and the steam vessel 80 are interconnected, with a pipe having a water supply tube 73 for supplying water from the bottom of the water tank 70 to the steam vessel 80 and an air tube 75 formed thereon. Accordingly, the air in the steam vessel 80 rises to the water tank 70 through the air tube 75 when the level of the water in the steam vessel 80 is lowered due to evaporation, while, the water in the water tank 70 flows into the steam vessel 80 through the water supply tube 73. When the level of the water in the steam vessel 80 becomes equal to the air tube 75, the air in the steam vessel 80 cannot flow into the water tank 70 due to the blockage of the water at the inlet of the air tube 75. This stops the supply of water from the water tank 70, so that the level of the steam vessel 80 can be maintained constantly. For this purpose, the water inlet 71 should be closed after filling the water tank with water.

[0037] A steam spray opening 83 is formed at the bottom of the suction unit body 60 for spraying the steam toward the object to be cleaned.

[0038] The steam of high temperature and high pressure can be used effectively because the steam generated from the steam vessel 80 is sprayed toward the object to be cleaned at the nearest position thereof, thereby improving the sterilization and insect-killing effect.

[0039] The reference numeral 93 is an electric cord connected to the carbon plates.

[0040] As described above, the steam-sterilizing vacuum cleaner according to the present invention can improve economical efficiency with a simple structure over the prior art, by adopting a steam-generating unit of chemical reaction. In addition, the present invention provides greater improvement in sterilization and cleaning effect. Accordingly, it is obvious to those skilled in the art that the steam-sterilizing vacuum cleaner of the present invention would be great successful on the market.

[0041] Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.