Vacuum cleaner

A vacuum cleaner including a main vacuum cleaner body having a plurality of caster mounting portions, respectively accommodating a caster, provided on a lower case of the vacuum cleaner main body, with the suction hose being turnably mounted substantially at a central portion of the upper case of the vacuum cleaner main body. A distance between an installation position of the suction hose and the respective caster mounting portions is substantially equal such that when the vacuum cleaner main body collides with an obstacle located on a surface to be cleaned by the vacuum cleaner, the suction hose can move easily and the vacuum cleaner main body can move and turn easily in a pulling direction of the suction hose to avoid the obstacle.

BACKGROUND OF THE INVENTION 
The present invention relates to a vacuum cleaner for cleaning a floor, 
tatami, and carpet and, more particularly, to a vacuum cleaner including a 
plurality of caster mounting means respectively mounting casters directly 
on a cleaner main body without providing a caster mounting base. 
A vacuum cleaner is proposed in, for example, Japanese Utility Model 
Publication No. 29421/1968, wherein a cleaner main body of the vacuum 
cleaner is turnably supported on a wheel mounting base having casters for 
enabling a moving of the vacuum cleaner over the surface to be cleaned. 
In the above proposed vacuum cleaner, since a wheel mounting base is added 
to the generally provided vacuum cleaner structure, the weight and height 
of the cleaner main body of the vacuum cleaner is increased, thereby 
adversely affecting handling of the vacuum cleaner. 
In the proposed vacuum cleaner, a plurality of caster mounting means for 
respectively mounting the casters are installed integrally in the wheel 
mounting base, with the casters being adapted to run along the surface to 
be cleaned. The wheel mounting base can turn independently relative to the 
cleaner main body of the vacuum cleaner. Namely, the plurality of casters 
can move and run individually relative to the cleaner main body of the 
vacuum cleaner. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a vacuum cleaner which 
improves the overall handling of the vacuum cleaner. 
Another object of the present invention is to provide a vacuum cleaner 
wherein a cleaner main body of a vacuum cleaner can run smoothly on a 
surface to be cleaned without the main body of the vacuum cleaner tilting 
or otherwise being displaced from a normal operating position. 
A further object of the present invention is to provide a vacuum cleaner 
wherein a cleaner main body of the vacuum cleaner can more readily avoid 
obstacles normally encountered during a vacuuming operation. 
A further object of the present invention is to provide a vacuum cleaner 
having a reduced weight and reduced height of the cleaner main body. 
In accordance with the present invention, a vacuum cleaner comprises a 
cleaner main body, a suction hose for introducing dust into the cleaner 
main body and moving means for enabling the cleaner main body to be moved 
over the surface to be cleaned. The suction hose is turnably mounted at a 
substantially central portion of an upper face of the cleaner main body, 
and the cleaner main body is turnable by the cooperation between the 
moving means and an obstacle on the surface being cleaned. 
When an operator pulls the suction hose, since the suction hose is mounted 
at a substantially central portion of the upper face of the cleaner main 
body, the suction hose can move easily in a pulling direction, and by the 
moving means, the cleaner main body can move smoothly in the pulling 
direction. 
During a vacuuming, the cleaner main body may collide with an obstacle on 
the cleaning surface, then the cleaner main body can turn around the hose 
mounting portion of the suction hose, and, by avoiding the obstacle, the 
cleaner main body can move or turn in the pulling direction of the suction 
hose. Further, since there is no wheel mounting base on the cleaner main 
body, the weight and height of the cleaner main body can be reduced. 
According to the present invention, in a vacuum cleaner comprising a 
cleaner main body, a suction hose for introducing dust into the cleaner 
main body and a moving means for enabling a moving of the cleaner body 
over a surface to be cleaned, the suction hose is turnably mounted on a 
substantially central portion of an upper face of the cleaner main body, 
with the cleaner main body being turnable by cooperation of the moving 
means with an obstacle on the surface to be cleaned.

DESCRIPTION OF THE INVENTION 
As shown in FIG. 1, a substantially round cleaner main body 1 of the vacuum 
cleaner of the present invention includes an upper case 2, a dust 
collecting cover 3 and a lower case 4. An upper surface of the upper case 
2 is formed with a smoothly curved shape. 
An electric driven blower motor 5 is installed in an inner portion of the 
cleaner main body 1, with the electric driven blower motor 5 generating a 
suction force. A dust collecting portion 7, accommodating a filter member 
6, and a cord reel winding apparatus 9 for winding a power source cord 8 
are also installed in the cleaner main body 1. 
The electric driven blower motor 5 is elastically supported by a large 
vibration-suppressing rubber member 10 and a small vibration-suppressing 
rubber member 11, with the vibration-suppressing members 10, 11 preventing 
a direct transfer of vibrations to an outside portion of the cleaner body 
1. 
Four caster mounting portions 12a, 12b, 12c and 12d are provided on the 
lower case 2 and respectively turnably support four casters 13 as moving 
means for the cleaner body 1, with a bumper 14 being provided for 
preventing scratching or damaging of furniture. The casters 13 are mounted 
on a bottom portion of the lower case 3 of the cleaner main body 1. The 
caster mounting portions 12a, 12b, 12c and 12d project radially outwardly 
from a side portion of the cleaner main body 1. 
An inner wall portion 15 is provided on an inner side of the dust 
collecting cover 3, and, along with a packing or seal member 16, forms an 
air-tight seal for the dust collecting portion 7. The dust collecting 
portion 7 is opened and closed by manipulating a clamp 17. 
The dust collecting cover 3 is positioned at an upper portion of the 
cleaner main body 1 and a hose mounting portion 18 is provided at a 
substantially central portion of the upper case 2 of the cleaner main body 
1. The hose mounting portion or hose installing portion 18 is turnably 
connected to a suction hose 20 by a substantially L-shaped hose coupling 
19, as shown in FIG. 1, such that the suction hose 20 is turnable about a 
turning axis Q. 
The turning axis Q of the hose coupling 19 extends substantially parallel 
to a mounting axis P of each of the caster mounting portions 12a, 12b, 12c 
and 12d. The hose coupling 19 may be rotatably over substantially a 
360.degree. angle (not shown) may be limited to substantially two 
substantially a 180.degree. angle. 
Further, distances d1, d2, d3, and d4 between the hose mounting portion at 
each of the plurality of caster mounting portions 12a, 12b, 12c, 12d are 
set so as to have substantially the same length, as shown in FIG. 2. 
When an operator is vacuuming in a direction of the arrow A (FIG. 2) and 
moves the vacuum cleaner in a direction of the arrow B, since the suction 
hose is turnable at the substantially central portion of the upper portion 
of the cleaner main body 1, via the hose coupling 19, the suction hose can 
be rotated easily to a position indicated in phantom line and can be 
turned in the direction of the arrow B. 
When the operator then pulls the cleaner main body 1 in the direction of 
the arrow B and encounters an obstacle 21, as shown in FIG. 3, a collision 
point 21a of the caster mounting portion 12b against the obstacle 21 works 
as fulcrum point and then the cleaner main body can be rotated around the 
hose mounting portion 18 as a center for turning and the cleaner main body 
1 can be moved so as to avoid the obstacle 21 by the cleaner main body 
assuming a position indicated in phantom line in FIG. 3. 
Further since distances d.sub.1, d.sub.2, d.sub.3, and d.sub.4 between the 
hose mounting portion 18 and each of the plurality of caster mounting 
portions 12a, 12b, 12c and 12d are substantially the same, that is, d.sub. 
=d.sub.2 =d.sub.3 =d.sub.4, when any one of the caster mounting portions 
12a, 12b, 12c, or 12d collides with the obstacle 21, it is possible to 
avoid the obstacle 21 by virtue of substantially the same force or 
substantially the same moment. 
Further, since the distances d.sub.1, d.sub.2, d.sub.3, and d.sub.4 between 
each of the caster mounting portions 12a, 12b, 12c, and 12d and the hose 
mounting portion 18 are substantially the same length, regardless of which 
of the caster mounting portions 12a, 12b, 12c or 12d may hit against the 
obstacle 21, the cleaner main body 1 can avoid the obstacle 21 by 
application of substantially the same force due to the substantially same 
distance ratio, and, accordingly, the operation feeling for the operator 
remains the same. 
The significant advantages of the vacuum cleaner of the present invention 
are best understood when compared with the comparative examples of FIGS. 4 
and 5. 
The vacuum cleaner shown in FIG. 4 has a round shaped cleaner main body 
101. The vacuum cleaner comprises a cleaner main body 101 and four caster 
mounting portions 112a, 112b, 112c, and 112d. A hose coupling 119 is 
mounted on the cleaner main body 101. A suction hose 120 is connected to 
the hose coupling 119. A hose mounting portion 118 for the suction hose 
120 or the hose installation position is not disposed at a central portion 
of the cleaner main body 101 but is offset to a side portion of the upper 
face of the cleaner main body 101. 
In this vacuum cleaner structure, the distance d.sub.13 between the caster 
mounting portion 112c and the hose mounting portion 118 is equal to the 
distance d.sub.14 between the caster mounting portion 112d and the hose 
mounting portion 118. 
However, both the distance d.sub.11 between the caster mounting portion 
112a and the hose mounting portion 118 and the distance d.sub.12 between 
the caster mounting portion 112b and the hose mounting portion 118 differ 
from the distance d.sub.13 between the caster mounting portion 112c and 
the hose mounting portion 118 or the distance d.sub.14 between the caster 
mounting portion 112d and the hose mounting portion 118, respectively. 
Namely, the relationship between the distance is d.sub.11 &lt;d.sub.13 
=d.sub.13 &lt;d.sub.12. 
In the above described vacuum cleaner having the round shape cleaner main 
body 101, when the caster mounting portion 112a, the caster mounting 
portion 112c and the caster mounting portion 112d, each of which has the 
shorter distance d.sub.11, d.sub.13 and d.sub.14 in comparison with the 
distance d.sub.12, hits against an obstacle 121, the force required for 
the avoidance of the obstacle 121 becomes a moment force. 
For example, as shown in FIG. 4, when the caster mounting portion 112a hits 
the obstacle 121, then a collision portion 121 becomes a fulcrum point. 
Therefore, since the distance ratio becomes large or the distance d.sub.11 
is shorter than that of the distance d.sub.12, the operation 
characteristic property of the vacuum cleaner may be lowered. 
The vacuum cleaner shown in FIG. 5 has an oval shaped cleaner main body 201 
and comprises a cleaner main body 201 and four caster mounting portions 
212a, 212b, 212c, and 212d. A hose coupling 219 is mounted on the cleaner 
main body 201. A suction hose 220 is connected to the hose coupling 219. A 
hose mounting portion 218 for the suction hose 220 or the hose installing 
position is not disposed at a central portion of the cleaner main body 201 
but is offset to a side portion of the upper face of the cleaner main body 
201. The distance d.sub.21 between the caster mounting portion 112a and 
the hose mounting portion 218 is equal to the distance d.sub.22 between 
the caster mounting portion 212b and the hose mounting portion 218. The 
distance d.sub.23 between the caster mounting portion 212c and the hose 
mounting portion 218 is equal to the distance d.sub.24 between the caster 
mounting portion 212d and the hose mounting portion 218. 
However, the distance d.sub.21 between the caster mounting portion 212a and 
the hose mounting portion 218 or the distance d.sub.22 between the caster 
mounting portion 212b and the hose mounting portion 218 differs from the 
distance d.sub.23 between the caster mounting portion 212c and the hose 
mounting portion 218 or the distance d.sub.24 between the caster mounting 
portion 212d and the hose mounting portion 218. Namely, the relationship 
between these distance is d.sub.21 =d.sub.22 &lt;d.sub.23 =d.sub.24. 
With the oval shaped cleaner main body 201 when the caster mounting portion 
212a and the caster mounting portion 212b, each of which has the shorter 
distances d.sub.21 and d.sub.22, compared with the distances d.sub.23 and 
d.sub.24 hits the obstacle 221, the force for requiring 221 becomes a 
moment force. 
For example, as shown in FIG. 5, when the caster mounting portion 212b hits 
the obstacle 221, the collision portion 221a becomes a fulcrum point for 
turning the cleaner main body 201. Therefore, since the distance ratio 
becomes large or the distance d.sub.22 is shorter than that of the 
distance d.sub.23, the operation characteristic property of the vacuum 
cleaner may be lower. 
In the present invention, even when the caster mounting portions 12 do not 
project radially outwardly from the cleaner main body, if a bumper member 
14 (FIG. 1) is provided at an outer peripheral portion of the cleaner main 
body 1, the avoidance of the obstacle can nevertheless be achieved in the 
following manner. 
When one of the caster mounting portions 12 collides against the obstacle 
21, the cleaner main body can rotate and run forward around the collision 
portion 21a as a fulcrum point for the turning. Then the effects similar 
to the above stated embodiment in which the caster mounting portions -2 
project toward the outside portion of the cleaner main body 1, in other 
words, the avoidance characteristic property of the obstacle 21 and the 
cleaner main body 1 can be obtained. 
When the vacuum cleaner has no dust collecting portion 7 installed in the 
cleaner main body, in other words, the dust collecting portion 7 is 
provided separately from the cleaner main body 1 at a front portion of the 
suction hose, the height of the cleaner main body 1 can be reduced as the 
cleaner main body 1 becomes more stable. 
Since the suction hose 20 is turnably mounted substantially at the central 
portion of the upper face of the cleaner main body via the hose coupling 
19, the hose coupling 19 can rotate easily toward the operator pulling 
direction, and, accordingly, the cleaner main body can follow and move 
smoothly toward the operator.