Abstract:
A vacuum cleaner containing an air passage system which is modified to increase the amount and speed of air drawn into the vacuum cleaner without increasing the capacity of the motor, whereby the performance of the vacuum cleaner is enhanced.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a vacuum cleaner, and more particularly, to a passage system of a vacuum cleaner in which an air passage system is modified to increase an amount and speed of air drawn into a vacuum cleaner without having to increase a capacity of a motor so that the performance of a vacuum cleaner is enhanced. 
     2. Description of the Related Art 
     Conventional vacuum cleaners are classified, depending upon a use and a shape, into a cylindrical vacuum cleaner which is generally employed at home, a pot-type vacuum cleaner, which is generally known as a canister vacuum cleaner, for a large places such as a place of business that requires a large capacity, and a portable vacuum cleaner which is easily carried around and employed for a specified purpose (such as a vehicle). 
     Among various kinds of vacuum cleaners, in case of a rechargeable vacuum cleaner such as the portable vacuum cleaner equipped with a rechargeable battery, it is difficult to produce an output of a sufficient level when using the vacuum cleaner due to the limitation of a capacity of a battery. 
     FIG. 1 is a schematic cross-sectional view illustrating a construction of a passage system of the conventional vacuum cleaner. 
     Referring to FIG. 1, the passage system of the conventional vacuum cleaner comprises a suction motor  10  which is installed on an upper end of the vacuum cleaner to provide a suction force for sucking the outside air into the vacuum cleaner, a suction fan  20  which is placed below the suction motor  10  and blades for sucking the outside air using rotating force of the suction motor  10 , a dust filter  30  which is placed below the suction fan  20  to filter dust contained in the outside air sucked by the suction fan  20 , a dust-collecting bucket  40  which is positioned below the dust filter  30  to collect dust and the like filtered by the dust filter  30 , and a suction nozzle  50  which is arranged below the dust collecting bucket  40  to elevate the speed of flow of the outside air sucked from the outside by the suction fan  20 , up to a predetermined value. 
     Operations of the passage system of the conventional vacuum cleaner according to the aforementioned configuration is described hereinafter. When a user turns on the vacuum cleaner to perform a cleaning work, the suction motor  10  is initiated. The Rotating force of the suction motor  10  is transferred to the suction fan  20  which is rotatably attached to a lower end of the suction motor  10 . Thereafter, as the suction fan  20  rotates, a low-pressure space is formed below the suction motor  10  to draw in the air from the outside into the vacuum cleaner. 
     As the air is sucked in from the outside toward the low-pressure space, dust and other particles are also sucked into the vacuum cleaner along with the outside air through the suction nozzle  50 . 
     The outside air is then directed to the dust filter  30 . In the dust filter  30 , while air can freely pass through the dust filter  30 , dust and the particles having a size larger than that of meshes of the dust filter  30 , are filtered by the dust filter  30 . 
     Dust and other particles which did not pass through the dust filter  30 , drop down to be collected in the dust collecting bucket  40 , whereby one cycle of operations of the vacuum cleaner is completed. 
     Also, the air which passed through the dust filter  30 , is exhausted to the outside after sequentially passing through the suction fan  20  and the suction motor  10 . While the air passes through the suction motor  10 , heat generated by the suction motor  10  is cooled. 
     While undergoing time serial sequences as described above, dust and other particles contained in the outside air, are filtered by the dust filter  30 . If dust and the particles are collected in the dust-collecting bucket  40  built up to the point in which in flow of the air is effected and degrade an efficiency of the vacuum cleaner, a user of the vacuum cleaner should empty out the dust-collecting bucket  40 . 
     Since the air, which is discharged to the outside after passing through the suction motor  10 , flows at a high speed, the air retains a substantial amount of kinetic energy which could be utilized to improve the efficiency. However, the passage system of the conventional vacuum cleaner dose not employ any means to reuse the air having kinetic energy. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a passage system of a vacuum cleaner, which enables the air to be exhausted is utilized again to provide an additional source of energy for the vacuum cleaner. And, in the case of a rechargeable vacuum cleaner wherein an output cannot be raised beyond a predetermined level due to the limitation within its own configuration, the passage system of the vacuum cleaner in accordance with the present invention allows a cleaning work to be performed in more efficient manner with the same power supply source. 
     In order to achieve the above object, the present invention provides a passage system of a vacuum cleaner, comprising: an ejector suction passage which is connected to one end of an outer surface of a motor case to reutilize air which has been exhausted from a suction motor; an ejector formed at the end of the ejector suction passage for accumulating air that has passed through the ejector suction passage; an ejector nozzle formed at one end of the ejector for exhausting the air at a high speed and under a low pressure; a second suction passage having one end placed at a predetermined distance from the ejector nozzle and the other end connected to a dust collecting bucket, such that the air discharged from the ejector nozzle and the air existing in an ejector chamber are simultaneously drawn in together into an ejector chamber and thereafter flows in the direction of a suction motor, an ejector chamber which is formed in the inside of the ejector nozzle, and one end of the second suction passage is connected in the ejector chamber so that an inside of the ejector chamber remains under low pressure; a second suction nozzle formed at a predetermined position in the ejector chamber to draw in the outside air at a high speed; a first suction nozzle placed at a predetermined position of the vacuum cleaner to draw the air in at a high velocity by a suction force generated by the suction motor; and a first suction passage having one end which is fastened to the first suction nozzle and the other end is connected to a predetermined part of the dust collecting bucket, in a manner such that outside air which is drawn in via the first suction nozzle, is guided toward the suction motor. 
     By the feature of the present invention, the passage system of a vacuum cleaner according to the present invention provides advantages in that, since energy, which is contained in air discharged through a suction motor, is utilized again, cleaning performance of the vacuum cleaner can be improved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with the drawings, in which: 
     FIG. 1 is a schematic cross-sectional view illustrating a construction of a passage system of a conventional vacuum cleaner; 
     FIG. 2 is a schematic cross-sectional view illustrating a construction of a passage system of a vacuum cleaner in accordance with an embodiment of the present invention; and 
     FIG. 3 is a schematic cross-sectional view illustrating a construction of a passage system of a vacuum cleaner in accordance with another embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. 
     FIG. 2 is a schematic cross-sectional view illustrating a construction of a passage system of a vacuum cleaner in accordance with an embodiment of the present invention. 
     Referring to FIG. 2, in the present invention, in order to allow the outside air to be sucked into the vacuum cleaner, two suction paths are included as described below. 
     First, the passage system of a vacuum cleaner according to the present invention comprises a suction motor  10 , a suction fan  20 , a dust filter  31 , a dust collecting bucket  41 , a fan suction passage  42 , a motor case  11 , a plurality of discharging holes  11   a , an ejector suction passage  62 , an ejector  60 , an ejector nozzle  61 , an ejector chamber  63 , a second suction nozzle  64  and a second suction passage  65 . 
     The suction motor  10  is installed adjacent to an upper end of the vacuum cleaner to provide the suction force for draw the outside air into the vacuum cleaner. The suction fan  20  is located on an upper end of the suction motor  10  and has blades which receive the suction force from the suction motor  10  and thereby suck the outside air. The dust filter  31  is arranged above the suction fan  20  to filter out dust and other particles contained in the outside air drawn in by the suction fan  20 . The dust filter  31  has a doughnut-shaped configuration. The dust-collecting bucket  41  is positioned below the dust filter  31  to collect dust and other particles filtered by the dust filter  31 . The dust collecting bucket  41  has a hollow configuration. The fan suction passage  42  is placed at the center portion of the dust collecting bucket  41  in a manner such that outside air that has been through the filtering process to remove the dust and the like by the dust filter  31 , flows through the fan suction passage  42  toward the suction fan  20 . The fan suction passage  42  has a cylindrical shaped which is opened at an upper end thereof. The motor case  11  is formed to have a cylindrical shape to accommodate the suction motor  10 . The plurality of discharging holes  11   a  are formed on a circumferential outer surface of the motor case  11  at predetermined places in a manner to exhaust the air that has been pressurized while passing through the suction fan  20  to the outside. The ejector suction passage  62  serves as an exhausting passage and is connected at one end thereof to the circumferential outer surface of the motor case  11  at a predetermined place in a manner such that the air which has been passed through the suction fan  20 , can be reutilized. 
     The ejector  60  is formed at the other end of the ejector suction passage  62  to exhaust the air which passed through the ejector suction passage  62 . The ejector nozzle  61  is placed at the lower end of the ejector  60  to further pressurize the air which has been already pressurized while passing through the suction fan  20 , and then exhaust the air at a high velocity. The ejector chamber  63  is defined in a manner such that an inside of the ejector chamber  63  remains under a low pressure by the air which is ejected from the ejector nozzle  61  at a high speed. The second suction nozzle  64  is formed at a lower end of the ejector chamber  63  in a manner such that outside air can be sucked therein. The second suction passage  65  is connected at one end thereof to the duct collecting bucket  41  in a manner such that air which is ejected therein from the ejector nozzle  61  and sucked therein from the ejector chamber  63 , is guided toward the suction fan  20 . 
     A second suction path operates in the same manner as a suction path of the conventional vacuum cleaner. The second suction path according to the present invention is formed with a first suction nozzle  71  and a first suction passage  72 . The first nozzle  71  directly receives the suction force generated by the suction motor  10  to draw in the outside air containing dust and other particles with intensive force. One end of the first suction passage  72  is connected to the dust-collecting bucket  41  and the other end is connected to the first suction nozzle  71 , so that the outside air, which is drawn into the vacuum cleaner by the first suction nozzle  71 , can pass through the first suction passage  72 . 
     It is preferred that the first suction nozzle  71  and the second suction nozzle  64  are formed at the lowermost end of the entire vacuum cleaner structure to allow dust and the like existing on a floor to be easily drawn in along with outside air. 
     Hereinafter, operations of the passage system of a vacuum cleaner according to the present invention, constructed as mentioned above, will be described in detail. 
     When a user turns on the vacuum cleaner to perform a cleaning work, the suction motor  10  rotates, and at the same time, the suction fan  20  which is connected to the suction motor  10  also rotates. 
     If the suction fan  20  is rotated, the outside air is drawn in and passes through the first suction nozzle  71 , the first suction passage  72 , the dust collecting bucket  41 , the dust filter  31  and the fan suction passage  42  in order. Upon reaching the suction fan  20  and the suction motor  10  after passing through the fan suction passage  42 , air cools the suction motor  10  and at the same time is pressurized by the suction motor  10 . 
     In the course of the suction process, dust and the like which are contained in the outside air, are filtered by the dust filter  31 . As dust and other particles are piled up in the dust-collecting bucket  41 , a cycle of the second outside air suction path is completed. 
     Hereinafter, the operation of the first outside air suction path is described in detail. The motor case  11  which accommodates the suction motor  10 , is attached with the plurality of discharging holes  11   a  in which predetermined amount of air that has been pressurized while passing through the suction fan  20 , is discharged to the outside, and the remaining predetermined amount of the air which has been pressurized while passing through the suction fan  20  flows into the ejector  60  through the ejector suction passage  62 . A ratio between the preselected amount which is discharged to the outside through the plurality of discharging holes  11   a  and the predetermined amount which flows out through the ejector suction passage  62 , can be adjusted according to the needs by adjusting the size and the number of the discharging holes  11   a.    
     The air, which flows into the ejector  60 , is exhausted through the ejector nozzle  61  formed at the free end of the ejector  60 . Since the air is exhausted under a high pressure, it is to be readily understood that the surrounding area near the ejector nozzle  61  is maintained under a remarkably low pressure as explained in the Bernoulli&#39;s theorem, and the inside of the ejector chamber  63  which includes the discharging end of the ejector  60 , also remains in a significantly low pressure. 
     Due to the low pressure environment which has been created in the inside the ejector chamber  63  as described above, the outside air is drawn into the vacuum cleaner through the second suction nozzle  64  which is formed at a predetermined position in the ejector chamber  63 , as in the case of the first suction nozzle  71 . 
     This function will be described hereafter in further detail using the Bernoulli&#39;s theorem. 
     The Bernoulli&#39;s theorem is expressed as given below: 
     
       
           H=P/γ+V   2 /2 g+Z= constant, 
       
     
     where H is a total head, P is a pressure at a corresponding point, γ is a specific weight of fluid, V is a flow velocity, g is an acceleration of gravity, and Z is a height of fluid on a reference plane. The Bernoulli&#39;s theorem applies to all incompressible fluid. According to the Bernoulli&#39;s theorem, water heads are divided into a pressure head (P/γ) due to a pressure of fluid, a velocity head (V 2 /2g) due to a flow velocity of the fluid, and a position head (Z) due to a height of the fluid. The Bernoulli&#39;s theorem shows that the total sum of the three heads is always held equal at any point in the fluid. 
     Describing again operations of the passage system of a vacuum cleaner according to the present invention on the basis of the Bernoulli&#39;s theorem as deliberated above, since the air existing in the ejector  60  has a low flowing velocity, a high pressure and a constant height, the air in the surrounding area near the ejector nozzle  61 , more particularly the outlet end of the ejector  60  having a high velocity at a constant height, has a low pressure when considering the Bernoulli&#39;s theorem. 
     As a result, a low pressure space of a sufficient level is created in between the ejector nozzle  61  and the second suction passage  65 , thereby the low pressure environment is created in the inside the ejector chamber  63  that includes the low pressure space. 
     The second suction nozzle  64  is placed below the ejector chamber  63  to intake the outside air which then gets mixed up with the air exhausted from the ejector nozzle  61  before passing through the second suction passage  65 . Consequently, in the passage system of a vacuum cleaner according to the present invention includes two suction nozzles that are formed at the outside air suction paths through which dust and the like can be sucked into the vacuum cleaner. Particularly, since the predetermined amount of air that has passed through the suction motor  10  is utilized to draw in the outside air, an efficiency of the vacuum cleaner is increased. 
     As described above, in the passage. system of a vacuum cleaner in accordance with the embodiment of the present invention, since the plurality of suction nozzles are formed, a cleaning capability of the vacuum cleaner for sucking the outside air has been substantially increased without using an additional source of energy, but by only modifying a passage system of the conventional vacuum cleaner. 
     FIG. 3 is a schematic cross-sectional view illustrating a construction of a passage system of a vacuum cleaner in accordance with another embodiment of the present invention. In the above-described first embodiment of the present invention, although it is possible to place the first suction passage  72  and the second suction passage  65  separately and connect to the dust collecting bucket  41  at different positions, this passage construction makes not only the passage system of a vacuum cleaner more complex but also a manufacturing procedure thereof complicated. In order to resolve this problem, in the second embodiment of the present invention, an outside air passage  70  in which the first suction passage  72  and the second suction passage  65  merge is independently formed. The passage system of a vacuum cleaner in accordance with the present invention allows the outside air containing dust and other particles to flow into the dust-collecting bucket  41  via the outside air passage  70 . 
     As a result, the passage system of a vacuum cleaner according to the present invention provides more powerful suction force for sucking the outside air through two sucking passages in the passage system, thus the cleaning process can be performed more quickly. Also, when compared with the conventional vacuum cleaner, less amount of input power is required for sucking the same amount of outside air thereby substantially saving energy. Moreover, in the case a rechargeable vacuum cleaner wherein the output of a motor cannot be raised beyond a predetermined level due to limitation within its own specification, greater cleaning capability can be accomplished when the passage system in accordance with the present invention is applied. 
     In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.