The present invention relates to a vacuum cleaner used in a general household.
A vacuum cleaner was hitherto constructed as shown in FIG. 54. This construction is described below.
As shown in FIG. 54, a blower 501 is disposed inside a cleaner main body 502, and a dust collector 504 incorporating a dust bag 503 is provided above the blower 501. The dust collector 504 and a suction unit 505 are connected through a hose 506. As indicated by the arrow in FIG. 54, dust is sucked together with air from the bottom 507 of the suction unit 505 by virtue of the blower 501, climbs up inside of the hose 506 by overcoming gravity, and is filtered by the dust bag 503 and captured inside the dust bag 503. The sucked air passes through the dust bag 503, runs through the inside of the blower 501, and is released from an exhaust port 508.
A vacuum cleaner incorporating a rechargeable secondary battery, and having a charging stand serving also as a supporting stand is constructed as shown in FIG. 55. A cleaner main body 509 accommodates a secondary battery and a blower (neither shown), and a suction tool 510 is tiltably provided at the lower part of the cleaner main body 509. A charging stand 511 is to charge the secondary battery contained in the cleaner main body 509, and this charging stand 511 has a mounting portion 512 for mounting the suction tool 510, and also has a box portion 513 having a charging power transformer and a charging terminal (neither shown).
When the suction tool 510 is put on the mounting portion 512 of the charging stand 511, the terminal of the cleaner main body 509 and the terminal of the charging stand 511 are electrically connected, so that the secondary battery is charged.
Also as shown in FIG. 56, by setting a cleaner main body 514 incorporating a secondary battery in a charger 515, the circuit connected to a blower 516 in the cleaner main body 514 is cut off by force, thereby changing over to the charging circuit.
When the cleaner main body 514 is set in the charger 515, a charging terminal 517a contacts with a deforming terminal 518a, and is deformed at the same time, so that the deforming terminal 518a is separated from a fixed terminal 518c. By this action, the blower 516 is put in closed circuit whether a switch 519 is on or off, and a charging circuit is established. That is, if attempted to charge while the switch 519 is turned on, the power consumption in the blower 516 exceeds the charging capacity of the charger 515, and thus it is not charged substantially, and is discharged completely when trying to use it the next time. This is to avoid such a problem, and by changing over the circuits, it is intended to charge securely regardless of the state of the switch 519.
However, in the conventional vacuum cleaner as shown in FIG. 54, since the blower 501 and the dust collector 504 are disposed above the suction unit 505, when moving the dust on the floor into the dust bag 503 in the dust collector 504, it is necessary to lift the dust upwardly by overcoming gravity, and the moving distance of the dust is long and a large pressure loss occurs, and therefore, the blower 501 is required to have sufficient suction power. Accordingly, a blower 501 exhibiting a large power consumption is required, and if the battery is used as the power source for the blower 501, sufficient suction power cannot be assured in relation to the battery capacity, size or other condition.
Therefore, using not only the suction power of the blower 501 but also the exhaust of the blower 501, a reflux type cleaner for enhancing the dust collecting performance must be designed in order to increase the dust collecting performance utilizing small power consumption. Many types of such reflux type cleaners have been proposed so far. Such proposals have many problems to be solved for practical use.
Besides, since the blower 501 is disposed in the cleaner main body 502, the weight and volume of the cleaner main body 502 are large, and the weight applied on handle 118 during use is great, whereby controllability of the vacuum cleaner is not favorable.
When turning the cleaner main body 502 backward by keeping the cleaner main body 502 nearly in a vertical state relative to the floor, since there is no obstacle behind the cleaner main body 502, the cleaner main body 502 is easy to turn, but when turning the cleaner main body 502 forward, the lower part of the cleaner main body 502 and the upper part of the suction unit 505 interfere with each other, and turning of the cleaner main body 502 is restricted. Accordingly, the reciprocating distance traveled by the cleaner main body 502 when holding the handle 118 is limited, and thus the floor area covered by the cleaner main body 502 is limited, whereby the number of times a reciprocating motion must be performed is increased, and thus it takes a longer time to clean the floor.
In the case of the vacuum cleaner using a battery as the power source for the blower, in the construction as shown in FIG. 55, the charging stand 511 for charging the battery is often put at a corner of a room or corridor, which is part of the cleaning area, and thus the large charging stand 511 is an obstacle when cleaning this area.
Or, when charging the battery incorporated in the vacuum cleaner in the construction shown in FIG. 56, the structure is complicated around the terminal for changing over the charging circuit, the number of terminals and wiring points is great, and there is a high possibility of the occurrence of defective charging and defective operation.
It is hence a first object of the invention to blow an exhaust against a floor to lift dust from the floor to enhance the dust collecting efficiency of a vacuum cleaner, and to decrease the temperature rise of a motor used for driving a dust scraper that is rotatably incorporated in a suction unit, whereby durability of the vacuum cleaner is enhanced.
It is a second object to improve the ease of handling the vacuum cleaner, by extending the distance that the cleaner main body may be reciprocated when holding the handle.
It is a third object to reduce the size of a charger for charging a secondary battery incorporated in the cleaner main body, so that the charger will not interfere with the cleaning of the area around the charger, thereby enhancing the ease of handling the vacuum cleaner, while also decreasing the material cost to present the vacuum cleaner at low price.
It is a fourth object to connect the cleaner main body and the charger only when the switch is cut off mechanically, and simplify the circuit construction, so as to charge the battery securely and enhance the ease of use of the vacuum cleaner at a low cost.
In the invention, in order to achieve the first object, a dust scraper that is rotatably driven by a motor is disposed in a suction unit, and dust is sucked in from the suction unit by the blower while exhaust of the blower is sent into the suction unit through an exhaust passage. The exhaust of the blower is blown to the motor, and also the exhaust is blown against the floor to lift the dust from the floor, and thus the dust collecting efficiency is enhanced by the synergistic action of scraping by rotation of the dust scraper and blowing of the exhaust. Moreover, the temperature rise of the motor can be decreased, so that durability of the vacuum cleaner may be enhanced.
To achieve the second object, in a cleaner main body having a suction port for sucking dust at a front side thereof and at least one of the dust collection chamber and blower at a rear side thereof, a handle arm is formed to rotate or oscillate over at least part of an outer circumference of the cleaner main body. Therefore when reciprocating the cleaner main body by holding a handle formed in the handle arm during a cleaning operation, the reciprocal moving distance is longer, and thus the number of times a reciprocating operation needs to be performed is decreased, so that ease of handling the vacuum cleaner may be enhanced.
To achieve the third object, a terminal of a charger is connected to a terminal connection unit provided in the cleaner main body which accommodates a secondary battery and the blower. The charger has a box portion for accommodating a power transformer, and the terminal projects from a side wall of this box portion. Therefore, the charger for charging the secondary battery, is reduced in size such that the charger is not an obstacle when cleaning the area around the charger, the ease of handling the vacuum cleaner is enhanced, and the material cost is decreased whereby the vacuum cleaner price can be lowered.
To achieve the fourth object, a terminal of a charger is connected to a terminal connection unit connected to a secondary battery of a cleaner main body that accommodates the secondary battery and a blower. The cleaner main body has a switch connected between the secondary battery and the blower, and a manipulation unit for this switch. An engaging portion is provided in this manipulation unit, and the engaging portion is engaged with an opposite engaging portion provided in the charger to set the cleaner main body on the charger, so that the engaging portion moves according to operation of the manipulation unit to prevent the engaging portion from being engaged with the opposite engaging portion when the switch is in an ON state. Therefore, only when the switch is cut off mechanically, can the cleaner main body and the charger be connected, and it is thus possible to securely charge the secondary battery in a simple and inexpensive circuit structure, whereby the ease of handling the vacuum cleaner is enhanced.