DESCRIPTION
CEILING FAN
TECHNICAL FIELD
The present invention relates to a ceiling fan hanging from a ceiling.
BACKGROUND ART
Conventionally, as one example of the ceiling fan of this kind, a
ceiling fan which informs that a mounting screw thereof is loose by means of
an alarm device (see patent document 1, for example).
The conventional ceiling fan is described below with reference to FIG.
24 of a side view of an essential portion of the ceiling fan. Pipe 101
penetrating a center of ceiling fan 100 is suspended by mounting clamp 103
through hemispherical flange 102. Mounting clamp 103 is mounted, by
coupling screw 106, on mounting plate 105 which is mounted on ceiling
surface 110 through wood screw 104. Microswitch 107 is provided on
mounting clamp 103 and actuator 108 of microswitch 107 abuts against a
ceiling surface.
According to conventional ceiling fan 100, when wood screw 104 used
to mount mounting plate 105 or coupling screw 106 which is used to mount
mounting clamp 103 on mounting plate 105 is loosened, the alarm device or
the like is operated through microswitch 107 to enhance a safety level.
However, a structure of ceiling fan 100 has a problem that when a shaft (not
shown) provided on a side of a motor and pipe 101 hanging from the ceiling
are connected to each other, if the shaft and pipe 101 are not sufficiently

fastened by a screw and not fixed to each other, a strength for holding ceiling
fan 100 becomes insufficient by repetition of stop of operation of the motor
and speed change of the motor, and the safety level of the hanging state is
lowered.
A patent document 2 discloses another conventional ceiling fan. If
this ceiling fan hangs from a ceiling and is operated, a large rocking motion
is generated in a ceiling fan body depending upon an installing place.
That is, since a plurality of fan blades constituting the ceiling fan
body are mounted at the installing place, unbalance is generated between
the plurality of mounted fan blades in many cases. If the unbalance is
generated between the mounted fan blades, a large rocking motion is
generated in the ceiling fan body when the ceiling fan is operated, a
connected portion of the ceiling fan body is abnormally worn by the rocking
motion, and this may lead to a falling accident of the body.
To avoid this point, in some ceiling fans, a wire or the like for
preventing the falling accident is fixed to the ceiling fan body, but there is
caused a problem that if an excessive load is applied to the wire for a long
term, the wire is cut and the ceiling fan body falls as a result.
[Patent Document 1] Japanese Patent No.3,032,325
[Patent Document 2] Unexamined Japanese Patent Publication
No.H03-294696
DISCLOSURE OF THE INVENTION
The present invention provides a ceiling fan comprising a motor
which rotates a plurality of blades provided in a horizontal direction, a shaft

projecting from an upper portion of the motor, a pipe which is connected to an
upper end of the shaft and which hangs from a ceiling surface, a connecting
rod for connecting the pipe and the shaft with each other via through holes
formed in the pipe and the shaft, respectively, a female screw which is
threadedly engaged with the connecting rod, a displacement-correspondence
tool which is displaced or which detects a displacement amount in
correspondence with a relative positional displacement amount between the
shaft and the pipe, and a power source control tool which controls
energization to the motor in accordance with the displacement of the
displacement-correspondence tool or the detected displacement amount.
According to this ceiling fan, when the female screw is not strongly
fixed to the connecting rod, an axial torque caused by a rotation force of the
motor is applied to a connected portion between the shaft and the pipe by
repetition of stop of operation of the motor and speed change of the motor,
the connecting rod or the through hole is gradually worn, and a safety level is
lowered. However, since energization to the motor is controlled by the
displacement-correspondence tool which corresponds to the relative
displacement amount between the shaft and the pipe, it is possible to
prevent a worn state of the connected portion from developing. As a result,
the strength for holding the ceiling fan and a hanging state having a high
safety level can be maintained.
Further, the present invention provides a ceiling fan comprising
connecting clamp fixed to a ceiling, and a ceiling fan body hanging from the
connecting clamp through a hanging device, wherein the hanging device
includes a first connecting portion which can be mounted on the connecting

clamp, and a second connecting portion provided on a lower portion of the
first connecting portion, the ceiling fan body includes a motor which rotates a
plurality of fan blades provided in a horizontal direction, a shaft projecting
from an upper portion of the motor, and a joint portion fixed to an upper
portion of the shaft, the joint portion is movably mounted on the second
connecting portion, and the ceiling fan further comprises an
abnormal-rotation detector which detects rotation of the ceiling fan body and
stops the motor when a body rotation-preventing device provided on the joint
portion and one of the first connecting portion or the second connecting
portion is released.
Since the ceiling fan includes the body rotation-preventing device
and the abnormal-rotation detector, when a large rocking motion is
generated in the ceiling fan body at the time of operation, the body
rotation-preventing device is released, and the ceiling fan body starts
rotating. Next, the abnormal-rotation detector detects the rotation of the
ceiling fan body and the operation of the motor can be stopped. Therefore,
even if the ceiling fan body is operated and a large rocking motion is
generated in a state where the fan blades are abnormally mounted, the
rocking motion is detected and the operation of the ceiling fan can be stopped.
Accordingly, the large rocking motion is generated in the ceiling fan body at
the time of operation, and this rocking motion can avoid a falling accident of
the body which may be caused by abnormal wear of the connected portion of
the ceiling fan body.
BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an entire ceiling fan according to a first
embodiment of the present invention;
FIG. 2 is a side view of an essential portion of the ceiling fan;
FIG. 3 is a side view of an essential portion of the ceiling fan shown
in FIG. 2 as viewed from a different direction;
FIG. 4 is a side view of an essential portion showing a relation
between a pipe and a displacement-correspondence tool of the ceiling fan
according to the first embodiment of the invention;
FIG. 5 is a side view of an essential portion showing a relation
between the displacement-correspondence tool and a power source control
tool of the ceiling fan;
FIG. 6 is a side view of an essential portion showing a displacement
state between the pipe and a shaft of the ceiling fan;
FIG. 7 is a side view of an essential portion showing a connected
state between a female connector and a male connector of the ceiling fan;
FIG. 8 is a side view of an essential portion showing a separated
state between the female connector and the male connector of the ceiling fan;
FIG. 9 is a side view of an essential portion showing a mounted state
of a flanged cap of a ceiling fan according to a second embodiment of the
invention;
FIG. 10 is a side view of an essential portion showing a relation
between a magnet and a metal plate of the ceiling fan;
FIG. 11 is a block circuit diagram of a ceiling fan according to a third
embodiment of the invention;
FIG. 12 is a block circuit diagram showing a relation between a

controller and a threshold value adjuster of the ceiling fan;
FIG. 13 is a side view of an essential portion showing rotation
between a magnet and a magnetic detector of the ceiling fan;
FIG. 14 is a side view of an essential portion showing a relation
between an infrared receiver, an infrared emitter and a reflector plate of the
ceiling fan;
FIG. 15 is a block circuit diagram showing a relation between a
controller and an alarm of the ceiling fan;
FIG. 16 is an appearance diagram showing a ceiling fan according to
a fourth embodiment of the invention;
FIG. 17 is a side view of an essential portion showing the ceiling fan;
FIG. 18 is a diagram of the ceiling fan as viewed from below;
FIG. 19 is an appearance diagram showing a ceiling fan according to
a fifth embodiment of the invention;
FIG. 20 is an appearance diagram showing an abnormal-rotation
detector of the ceiling fan;
FIG. 21 is an appearance diagram showing a ceiling fan according to
a sixth embodiment of the invention;
FIG. 22 is an appearance diagram showing a ceiling fan according to
a seventh embodiment of the invention;
FIG. 23 is an appearance diagram showing a ceiling fan according to
an eighth embodiment of the invention; and
FIG. 24 is a side view of an essential portion showing of a
conventional ceiling fan.

REFERENCE MARKS IN THE DRAWINGS
1 blade
2 motor
3, 51 shaft
4 ceiling surface
5 pipe
6 connecting rod
7 displacement-correspondence tool
7a pipe-side displacement-correspondence tool
7b shaft-side displacement-correspondence tool
8 power source control tool
8a power source supplying tool
8b power source receiving tool
9 end
10, 65 female connector
11, 66 male connector

12 through hole
13 female screw
14 flanged cap

15, 23, 70, 83 magnet
16, 72 metal plate

17 controller
18 threshold value adjustor
19 magnetic detector
20 reflector plate

21 infrared emitter
22 infrared receiver

24 infrared rays
25 tip end
26 flange
27 alarm

41 ceiling
42 connecting clamp
43 hanging device
44 ceiling fan body
45 first connecting portion
46 second connecting portion
47 hanging frame
48 pulley
49 shaft
50 spacer

52 notch
53 fan blade
54 joint portion
55 receiving portion
56 body rotation-preventing device
57, 57a, 57b, 57c, 57d abnormal-rotation detector
58 projection
59 groove
60 gap

61, 61b, 61c, 61d ball joint
62 angle portion
63, 63a, 63b, 63c, 63d first rotation detecting tool
64, 64a, 64b, 64c, 64d second rotation detecting tool

67 cord clip
68 cord
69 charging portion
71 first rotation detecting tool contact
73 second rotation detecting tool contact
80, 80c, 80d control device
81, 81c, 81d first detecting tool mounting portion
82, 82c, 82d first detecting tool detecting portion

84 magnetic detecting portion
85 threshold value adjustor
86 push-on switch

90 reflector plate
91 infrared emitter
92 infrared receiver
PREFERRED EMBODIMENTS FOR CARRYING OUT OF THE
INVENTION
Embodiments of the present invention are described below with
reference to the drawings.
(First Embodiment)
FIG. 1 is a side view of an entire ceiling fan according to a first

embodiment of the invention, and FIG. 2 is a side view of an essential portion
of the ceiling fan. Motor 2 of ceiling fan 200 rotatably supports a plurality
of blades 1 which are radially disposed in a horizontal direction and shaft 3
projects from an upper portion of motor 2. A lower end of pipe 5 having a
large diameter is connected to an upper end of shaft 3 having a small
diameter, and an upper end of pipe 5 is engaged with a fixing clamp (not
shown) fixed to ceiling surface 4, thereby hanging ceiling fan 200 from ceiling
surface 4.
FIG. 3 is a side view of an essential portion of the ceiling fan shown
in FIG. 2 as viewed from a different direction. Pipe 5 and shaft 3 are formed
with through holes 12, respectively, and are connected to each other by
bolt-like connecting rod 6 to penetrate through holes 12. Female screw 13 is
threadedly engaged with connecting rod 6, and pipe 5 and shaft 3 are fixed to
each other.
According to the first embodiment of the present invention, FIG. 4 is
a side view of an essential portion showing a relation between a pipe and a
displacement-correspondence tool of the ceiling fan, FIG. 5 is a side view of
an essential portion showing a relation between the
displacement-correspondence tool and a power source control tool of the
ceiling fan, and FIG. 6 is a side view of an essential portion showing a
displacement state between the pipe and a shaft of the ceiling fan.
Ceiling fan 200 includes displacement-correspondence tool 7 which is
displaced in correspondence with a relative positional displacement amount
between shaft 3 and pipe 5 or detects displacement amount Y, and power
source control tool 8 which controls energization to motor 2 in accordance

with the displacement of displacement-correspondence tool 7 or detected
displacement amount Y.
Displacement-correspondence tool 7 is provided so as to be divided
into shaft-side displacement-correspondence tool 7b provided on the side of
shaft 3 and pipe-side displacement-correspondence tool 7a provided on the
side of pipe 5.
Displacement-correspondence tool 7 is fixed with respect to end 9 of
pipe 5. Power source control tool 8 can be divided into power source
supplying tool 8a provided on pipe-side displacement-correspondence tool 7a
and power source receiving tool 8b provided on shaft-side
displacement-correspondence tool 7b.
According to the first embodiment of the present invention, FIG. 7 is
a side view of an essential portion showing a connected state between a
female connector and a male connector of the ceiling fan, and FIG. 8 is a side
view of an essential portion showing a separated state between the female
connector and the male connector of the ceiling fan.
Power source supplying tool 8a and pipe-side
displacement-correspondence tool 7a provided on the side of pipe 5 are
integrally formed together as female connector 10. Power source receiving
tool 8b and shaft-side displacement-correspondence tool 7b provided on the
side of shaft 3 are integrally formed together as male connector 11.
According to the above configuration, shaft 3 of motor 2 to rotate the
blades 1 hangs from pipe 5 which hangs from ceiling 4. At that time, an
upper portion of hollow shaft 3 having the small diameter is inserted into a
lower portion of hollow pipe 5 having the large diameter. Bolt-like

connecting rod 6 penetrates through holes 12 formed in shaft 3 and pipe 5,
the other end of connecting rod 6 is threadedly engaged with and fixed by
female screw 13, and shaft 3 is held. At that time, if female screw 13 is not
strongly fixed to connecting rod 6, a gap is generated between shaft 3 and
pipe 5.
That is, a bolt and the like is used as connecting rod 6 and a tip end of
the penetrating bolt is strongly fastened into a nut, thereby eliminating the
gap between shaft 3 and pipe 5. According to this configuration, even if an
axial torque caused by a rotation force of motor 2 is applied to a connected
portion between shaft 3 and pipe 5, shaft 3 is not rotated with respect to pipe
5, and connecting rod 6 or through hole 12 becomes less prone to be worn.
However, when the ceiling fan is installed, it is not always true that the bolt
is fastened strongly to such an extent that the gap between shaft 3 and pipe
5 is eliminated. When a gap is generated, the axial torque generated by the
rotation force of motor 2 is applied to the connected portion between shaft 3
and pipe 5 by repetition of stop of operation of motor 2 and speed change of
motor 2, connecting rod 6 or through hole 12 is gradually worn, and a
position of shaft 3 is lowered with respect to pipe 5. At that time, power
source control tool 8 controls energization to motor 2 in accordance with a
displacement state or detected displacement amount Y by
displacement-correspondence tool 7 which is displaced in correspondence
with relative displacement amount Y between shaft 3 and pipe 5 or which
detects detected displacement amount Y. This makes it possible to prevent
a worn state of the connected portion from developing.
Displacement-correspondence tool 7 can be divided into shaft-side

displacement-correspondence tool 7b and pipe-side
displacement-correspondence tool 7a. According to this configuration, when
pipe 5 and shaft 3 are connected to each other at the time of assembling
operation of a product at an installing place, they can be connected to each
other as the pair of the displacement-correspondence tools 7 at the same time.
Therefore, it is possible to prevent an operator or a user from forgetting to
mount displacement-correspondence tool 7. When pipe 5 and shaft 3 are
not properly connected to each other, power source control tool 8 controls the
energization to motor 2 in response to the relative positional displacement
between shaft 3 and pipe 5 caused by wear of connecting rod 6 or through
hole 12. As a result, it is possible to prevent ceiling fan 200 from being used
in a state where a safety level against a falling accident thereof is low.
By fixing displacement-correspondence tool 7 with reference to end 9
of pipe 5, it is possible to easily position displacement-correspondence tool 7
when displacement-correspondence tool 7 is assembled, and to enhance the
operability when the ceiling fan is installed or produced. Further, since it is
possible to fix displacement-correspondence tool 7 by abutting
displacement-correspondence tool 7 against end 9 of pipe 5,
displacement-correspondence tool 7 can precisely be positioned, and
detection precision of displacement or displacement amount Y which is to be
detected can be enhanced.
Power source control tool 8 is provided so as to be divided into power
source supplying tool 8a which is connected to a commercial power source
and power source receiving tool 8b connected to motor 2. Since power
source supplying tool 8a is mounted on pipe 5 and power source receiving

tool 8b is mounted on shaft 3, when shaft 3 and pipe 5 are connected to each
other, they function as a pair of displacement-correspondence tool 7 and
power source control tool 8.
That is, when pipe 5 and shaft 3 are not properly connected to each
other, if the position of shaft 3 is varied with respect to pipe 5 due to wear of
connecting rod 6 or through hole 12, energization to motor 2 is stopped by
power source control tool 8 which operates in association with
displacement-correspondence tool 7. As a result, it is possible to stop the
operation of ceiling fan 200 in a state where a safety level against a falling
accident thereof is lowered.
Ceiling fan 200 includes female connector 10 in which pipe-side
displacement-correspondence tool 7a and power source supplying tool 8a are
integrally formed together, and male connector 11 in which shaft-side
displacement-correspondence tool 7b and power source receiving tool 8b are
integrally formed together. According to this configuration, when a
dangerous state where shaft 3 is displaced downward relative to pipe 5 is
created, a strong downward force exceeding a permissible range is applied to
male connector 11 and female connector 10. Since male connector 11 and
female connector 10 are separated away from each other, conduction to motor
2 is cut off, and the operation of ceiling fan 200 can be stopped.
(Second Embodiment)
FIG. 9 is a side view of an essential portion showing a mounted state
of a flanged cap of a ceiling fan according to a second embodiment of the
invention. FIG. 10 is a side view of an essential portion showing a relation
between a magnet and a metal plate of the ceiling fan. In the second

embodiment of the invention, only points which are different from the first
embodiment are described.
Flanged cap 14 which covers tip end 25 of shaft 3 is fitted between
shaft 3 and pipe 5, and material of flanged cap 14 is synthetic resin.
Furthermore, flanged cap 14 is substantially integrally fixed to pipe
5, and they become pipe-side displacement-correspondence tool 7a.
Further, magnet 15 is provided on one of shaft-side
displacement-correspondence tool 7b and pipe-side
displacement-correspondence tool 7a, and metal plate 16 is provided on the
other tool.
According to this configuration, tip end 25 of shaft 3 is covered and
flanged cap 14 fitted between shaft 3 and pipe 5 is provided, thereby
protecting tip end 25 of shaft 3 and preventing tip end 25 from being
deformed. Flanged cap 14 has such a guiding function that when tip end 25
of shaft 3 is inserted into pipe 5, flanged cap 14 slides and positions of holes
are aligned with each other at a position where end 9 of pipe 5 abuts against
flange 26 of flanged cap 14. Therefore, the mounting operability of shaft 3
and pipe 5 can be enhanced.
According to ceiling fan 210, a length of pipe 5 may be changed
depending upon a height of a ceiling in some cases. If flanged cap 14
suitable for an inside dimension of pipe 5 is provided on shaft 3 of motor 2,
one of pipes 5 which has a length corresponding to an installation place can
freely be selected.
Furthermore, material of flanged cap 14 is synthetic resin. Even if
inner diameter size precision of metal pipe 5 and outer diameter size

precision of shaft 3 are low, a size and surface roughness can be absorbed by
synthetic resin flanged cap 14. By increasing a degree of intimate contact
between pipe 5 and shaft 3, connecting rod 6 or through hole 12 becomes less
prone to be worn.
When an axial torque caused by a rotation force of motor 2 is applied
to the connected portion between shaft 3 and pipe 5 by repetition of ON or
OFF of motor 2, a contact sound or a scratchy sound may be generated from a
gap or a backlash of the connected portion in some cases. However, since
the flanged cap 14 is made of synthetic resin, it functions as a cushioning,
and it is possible to prevent vibration from being transmitted, and to prevent
an unusual sound from being generated.
Flanged cap 14 is substantially integrally fixed to pipe 5 and they are
formed as pipe-side displacement-correspondence tool 7a. According to this
configuration, when connecting rod 6 or through hole 12 is worn and a
dangerous situation where pipe 5 and shaft 3 are displaced is generated,
flanged cap 14 is reliably displaced together with pipe 5. Therefore, it is
possible to precisely detect displacement amount Y between pipe 5 and shaft
3.
Shaft-side displacement-correspondence tool 7b and pipe-side
displacement-correspondence tool 7a are formed as a combination of magnet
15 and metal plate 16. Power source receiving tool 8b is provided directly
on or in the vicinity of shaft-side displacement-correspondence tool 7b, power
source supplying tool 8a is provided directly on or in the vicinity of pipe-side
displacement-correspondence tool 7a. According to this configuration, when
the ceiling fan is used as usual, magnet 15 clings to metal plate 16, and

power source supplying tool 8a and power source receiving tool 8b are
connected to each other. However, if connecting rod 6 or through hole 12 is
worn and displacement amount Y is increased, magnet 15 and metal plate 16
are separated from each other when downward gravity greater than the
magnetic force applied to magnet 15 and metal plate 16 is applied thereto,
and power source supplying tool 8a and power source receiving tool 8b are
separated from each other. Therefore, energization to motor 2 is cut off, and
ceiling fan 210 is safely stopped.
(Third Embodiment)
FIG. 11 is a block circuit diagram of a ceiling fan according to a third
embodiment of the invention. FIG. 12 is a block circuit diagram showing a
relation between a controller and a threshold value adjustor of the ceiling fan.
In the third embodiment of the invention, only points which are different
from the first embodiment are described.
The ceiling fan includes displacement-correspondence tool 7 which
detects displacement amount Y in correspondence with the relative
positional displacement amount between shaft 3 and pipe 5, and controller
17 which receives a detection value from displacement-correspondence tool 7
as an electric signal. When the detection value exceeds a threshold value,
controller 17 controls or stops energization to motor 2 through power source
control tool 8.
Threshold value adjustor 18 is provided on the input side of
controller 17 so that a threshold value can be adjusted.
FIG. 13 is a side view of an essential portion showing a relation
between a magnet and a magnetic detector of the ceiling fan of the third

embodiment of the invention. Ceiling fan 220 includes magnet 23 as
pipe-side displacement-correspondence tool 7a, and magnetic detector 19 as
shaft-side displacement-correspondence tool 7b. When a detection value of
magnetic detector 19 becomes equal to or lower than a threshold value,
controller 17 stops motor 2 or reduces the number of revolutions of motor 2.
FIG. 14 is a side view of an essential portion showing a relation
between infrared receiver and emitter, and a reflector plate of the ceiling fan
of the third embodiment of the invention. Ceiling fan 220 includes reflector
plate 20 as pipe-side displacement-correspondence tool 7a, and infrared
emitter 21 and infrared receiver 22 connected to controller 17 as shaft-side
displacement-correspondence tool 7b. When a detection value of infrared
receiver 22 is equal to or lower than a threshold value, controller 17 stops
motor 2 or reduces the number of revolutions of motor 2.
FIG. 15 is a block circuit diagram showing a relation between a
controller and an alarm of the ceiling fan of the third embodiment of the
invention. Ceiling fan 220 includes alarm 27 which informs a user of an
abnormal condition when ceiling fan 220 stops motor 2 or reduces the
number of revolutions of motor 2, and alarm 27 is provided in the vicinity of
displacement-correspondence tool 7.
According to the above-described configuration, ceiling fan 220
includes displacement-correspondence tool 7 which is displaced in
correspondence with a relative positional displacement amount between
shaft 3 and pipe 5, and controller 17 which receives a detection value from
displacement-correspondence tool 7 as an electric signal. Therefore,
operation of ceiling fan 220 can be controlled by controller 17, and settings of

the threshold value can also be changed in accordance with the positional
displacement amount. When shaft 3 and pipe 5 are displaced and the
detection value exceeds a set threshold value, controller 17 stops or controls
energization to motor 2 through power source control tool 8, and it is possible
to prevent a worn state of the connected portion from developing.
A threshold value which is to be compared with a displacement value
detected by displacement-correspondence tool 7 is preset in controller 17.
An adjustor is provided in an operating unit on the input side of controller 17
so that the set value of the threshold value can be adjusted. With this
configuration, when the installing operation during which pipe 5 and shaft 3
are connected to each other is completed at the installing place, it is possible
to set the threshold value corresponding to the detection value of
displacement-correspondence tool 7 using the adjustor of the operating unit
without making fine adjustments of displacement-correspondence tool 7.
Therefore, a complicated adjusting operation for making fine adjustments of
the connected portion after the installing operation becomes unnecessary,
and it is possible to easily carry out the installing operation for securing
safety.
Magnet 23 is provided as pipe-side displacement-correspondence tool
7a, and magnetic detector 19 connected to the input side of controller 17 is
provided as shaft-side displacement-correspondence tool 7b. When the
ceiling fan is used as usual, since magnet 23 is close to magnetic detector 19,
a detection value of magnetic detector 19 is high, and ceiling fan 220 is
operated normally. Even when connecting rod 6 or through hole 12 is worn
and the detection value of magnetic detector 19 becomes equal to or lower

than the threshold value, controller 17 stops energization to motor 2 or
reduces the number of revolutions of motor 2, thereby preventing a worn
state of the connected portion from developing and securing safety.
Reflector plate 20 is provided as pipe-side
displacement-correspondence tool 7a, and a pair of infrared emitter 21 and
infrared receiver 22 is provided on reflector plate 20 as shaft-side
displacement-correspondence tool 7b such that infrared emitter 21 and
infrared receiver 22 are opposed to each other at a shallow angle. Therefore,
when the ceiling fan is operated as usual, infrared rays 24 from infrared
emitter 21 are reflected on reflector plate 20, infrared rays 24 enter infrared
receiver 22 and therefore, the detection value of infrared receiver 22 is high
and the ceiling fan is operated normally.
When shaft 3 is displaced downward relative to pipe 5, however,
since a distance between infrared emitter 21 and reflector plate 20 is
increased, infrared rays 24 reflected on reflector plate 20 enter infrared
receiver 22 at a location separated away from a center of infrared receiver 22.
As a result, the detection value of infrared receiver 22 is largely reduced and
becomes equal to or lower than the threshold value, and controller 17 stops
energization to motor 2 or reduces the number of revolutions of motor 2,
thereby preventing a worn state of the connected portion from developing
and securing safety.
Alarm 27 for informing a user of an abnormal condition is provided in
the vicinity of displacement-correspondence tool 7. Therefore, when a
dangerous situation where shaft 3 is displaced downward relative to pipe 5 is
generated, alarm 27 is actuated when controller 17 stops energization to

motor 2 or reduces the number of revolutions of motor 2, and alarm 27
informs a user that the ceiling fan is abnormally stopped or is operating in a
situation corresponding to the abnormal condition. Since alarm 27 is
provided in the vicinity of displacement-correspondence tool 7, it is possible
to easily determine a location which should be checked, and to swiftly
prepare for an exchanging operation of a part or the like.
If an audio device using beeps or sound, or a visual display device
using LED blinking or character representation is used as alarm 27, it is
possible to inform a user of an abnormal condition.
(Fourth Embodiment)
FIG. 16 is an appearance diagram showing a ceiling fan according to
a fourth embodiment of the invention. FIG. 17 is a side view of an essential
portion showing the ceiling fan. FIG. 18 is a diagram of the ceiling fan as
viewed from below. According to ceiling fan 230, ceiling fan body 44 hangs
from connecting clamp 42 fixed to ceiling 41 through hanging device 43.
Connecting clamp 42 is a columnar wire material, an upper end
thereof is fixed to ceiling 41, and a lower end thereof is formed into a J-shape
using the wire material so that hanging device 43 can be hooked on the lower
end of the connecting clamp 42. Hanging device 43 includes first connecting
portion 45 in which connecting clamp 42 is hooked on an upper portion of
U-shaped hanging frame 47, and second connecting portion 46 in which joint
portion 54 is movably fitted to a lower portion of first connecting portion 45.
First connecting portion 45 includes columnar shaft 49 horizontally
fixed to hanging frame 47, disk-like pulley 48 which is rotatably inserted into
shaft 49 and which is provided at its central portion of its outer periphery

with a recessed groove, and two hollow columnar spacers 50 provided on both
ends of pulley 48. Shaft 49 is used for fixing pulley 48 in the vicinity of a
center of shaft 49, and is inserted into spacers 50.
Second connecting portion 46 is formed into a bowl-like shape for
movably holding a spherical surface. Receiving portion 55 having notch 52
is integrally formed on hanging frame 47, and shaft 51 can pass through
notch 52.
Ceiling fan body 44 includes a motor (not shown) which rotates a
plurality of fan blades 53 provided in the horizontal direction, columnar
shaft 51 projecting from an upper portion of the motor, and joint portion 54
including substantially hemispherical ball joint 61 fixed to an upper portion
of shaft 51. Joint portion 54 can movably be mounted on second connecting
portion 46.
That is, a spherical portion of ball joint 61 is movably fitted into
receiving portion 55.
The ceiling fan of the fourth embodiment of the invention is
characterized in that the ceiling fan includes abnormal-rotation detector 57
which detects a rotation of ceiling fan body 44 and stops the operation of the
motor when body rotation-preventing device 56 provided on joint portion 54
and on one of first connecting portion 45 and second connecting portion 46 is
released.
Body rotation-preventing device 56 is formed into a bowHike shape
for movably holding a spherical surface of second connecting portion 46.
Body rotation-preventing device 56 includes rectangular plate-like metal
projection 58, and groove 59 having substantially a rectangular cross section.

Projection 58 is integrally formed on receiving portion 55 having notch 52,
and shaft 51 can pass through notch 52. Groove 59 is formed in a vertical
direction to a substantially hemispherical surface of ball joint 61 which is
joint portion 54.
In a state where the spherical portion of ball joint 61 is movably
fitted into receiving portion 55 and in this fitting state, projection 58 is fitted
into groove 59 of ball joint 61, and gap 60 is provided between groove 59 and
projection 58.
Since gap 60 is provided between groove 59 and projection 58,
projection 58 can easily be fitted into groove 59 of ball joint 61 when the
spherical portion of substantially hemispherical ball joint 61 which is joint
portion 54 is movably fitted thereto.
When ceiling fan body 44 is operated, ball joint 61 is rotated by a
rotation force of the motor in a direction opposite to a rotation direction of
the motor of the horizontal direction. That is, when ball joint 61 is rotated
in a horizontal direction, an inner surface of groove 59 of ball joint 61 and an
angle portion 62 which intersects with an outer peripheral surface of ball
joint 61 come into contact with an end surface of projection 58.
That is, when ceiling fan body 44 rocks, the inner surface of groove 59
of ball joint 61 and angle portion 62 which intersects with the outer
peripheral surface of ball joint 61 come into contact with the end surface of
projection 58.
Since the contacting surfaces are the angle portion 62 of ball joint 61
and the end surface of projection 58, the contact area is small. Therefore, a
friction force is also small, and when ceiling fan body 44 is operated and

rocking motion is generated, ball joint 61 can more smoothly move on
receiving portion 55.
If ceiling fan body 44 is kept operating in a state where fan blades 53
are abnormally mounted, and when large rocking motion of ceiling fan body
44 is generated at the time of operation, angle portion 62 of ball joint 61 is
largely moved vertically by the rocking motion, and angle portion 62 and one
point of the end surface of projection 58 rub against each other. That is, the
one point of the end surface of projection 58 having a small area is worn
while angle portion 62 of ball joint 61 itself of an amount corresponding to
the vertical moving distance is also worn.
An example of material of ball joint 61 is nylon 66 in which glass
fiber is mixed. With this glass fiber, moving performance of ball joint 61
with respect to receiving portion 55 is enhanced, and it is also possible to cut
down metal.
According to this configuration, projection 58 which is body
rotation-preventing device 56 is cut down or broken off and as a result, body
rotation-preventing device 56 is released.
When angle portion 62 of ball joint 61 is brought into contact with the
end surface of projection 58 in this manner, projection 58 is cut down or
broken off. Thus, it is possible to sense a large rocking motion caused by
such a case that ceiling fan body 44 is kept operating in a state where fan
blades 53 are abnormally mounted.
When projection 58 is cut down or broken off and ceiling fan body 44
is rotated, abnormal-rotation detector 57 stops the operation of the motor.
Abnormal-rotation detector 57 includes first rotation detecting tool

63 and second rotation detecting tool 64. First rotation detecting tool 63 is
fixed to second connecting portion 46 and second rotation detecting tool 64 is
fixed to ceiling fan body 44.
First rotation detecting tool 63 and second rotation detecting tool 64
are connected to each other such that they can be separated from each other,
and they are also connecting portion of power source supply to the motor.
When ceiling fan body 44 rotates, first rotation detecting tool 63 and
second rotation detecting tool 64 are separated from each other by a
predetermined distance, thereby cutting off supply of power source to the
motor, and the operation of ceiling fan body 44 can be stopped.
First rotation detecting tool 63 is in conduction with the power source
and second rotation detecting tool 64 is in conduction with the motor.
Since first rotation detecting tool 63 located at an upper portion is in
conduction with the power source which is supplied from the ceiling, second
rotation detecting tool 64 located at a lower portion is in conduction with the
motor, and it is possible to easily wire.
First rotation detecting tool 63 and second rotation detecting tool 64
are connected to each other by a fitting force and they are in conduction with
each other. This fitting force is smaller than the rotation force of ceiling fan
body 44 when it rotates.
First rotation detecting tool 63 and second rotation detecting tool 64
are connected to each other and brought into conduction with each other by
the fitting force which is smaller than the rotation force of ceiling fan body 44
when it rotates. Therefore, when ceiling fan body 44 rotates, the connection
between first rotation detecting tool 63 and second rotation detecting tool 64

is released, the supply of power source to the motor is cut off, and the
operation of ceiling fan body 44 can be stopped.
More specifically, according to first rotation detecting tool 63, cord 68
connected to the power source is fixed to a side surface of hanging frame 47
by means of cord clip 67, female connector 65 is provided on a tip end of cord
68. According to second rotation detecting tool 64, male connector 66 is
fixed to a top surface of ceiling fan body 44, and male connector 66 is in
conduction with the motor.
First rotation detecting tool 63 which is in conduction with the power
source supplied from the ceiling is female connector 65. Therefore, when
ceiling fan body 44 rotates and connection between first rotation detecting
tool 63 and second rotation detecting tool 64 is released, since female
connector 65 is provided on the tip end of cord 68, female connector 65 can
move, and a charging portion is surrounded by female connector 65 and is
not exposed. As a result, charging portions do not come into contact with
each other, the supply of a power source to the motor can be cut off safely,
and the operation of ceiling fan body 44 can be stopped.
Male connector 66 which is second rotation detecting tool 64 is fixed
to the top surface of ceiling fan body 44 such that charging portion 69 on the
tip end of male connector 66 is inclined about 45° upward. Female
connector 65 which is first rotation detecting tool 63 is fixed to a tip end of
cord 68. Cord 68 is fixed to a side surface of hanging frame 47 at a position
above a position where male connector 66 is fixed and at a position rotated
90° on a horizontal plane into a rotating direction of fan blades 53.
According to this configuration, an angle of cord 68 fixed by cord clip

67 from female connector 65 which is fitted to male connector 66 and an
angle of charging portion 69 of male connector 66 are substantially the same.
Therefore, a rotation force when ceiling fan body 44 rotates is applied in
substantially the same direction as a direction in which fitted portions
between male connector 66 and female connector 65 are separated from each
other. Therefore, an unreasonable force is not applied to male connector 66,
and male connector 66 and female connector 65 can be disengaged from each
other.
(Fifth Embodiment)
FIG. 19 is an appearance diagram showing a ceiling fan according to
a fifth embodiment of the invention. FIG. 20 is an appearance diagram
showing an abnormal-rotation detector of the ceiling fan. In the fifth
embodiment of the invention, only points which are different from the fourth
embodiment are described. Ceiling fan 240 of the fifth embodiment of the
invention is different from ceiling fan 230 of the fourth embodiment of the
invention in that abnormal-rotation detector 57a connects first rotation
detecting tool 63a to second rotation detecting tool 64a each other through a
magnetic force.
That is, first rotation detecting tool 63a and second rotation detecting
tool 64a are connected to each other through the magnetic force and they are
in conduction with each other. More specifically, flat plate-like magnet 70 is
provided on a lower surface of first rotation detecting tool 63a, and first
rotation detecting tool contact 71 is provided in the vicinity of magnet 70.
Cord 68 is provided on an upper surface of first rotation detecting tool 63a,
and first rotation detecting tool contact 71 is connected to a power source.

Cord 68 is fixed to a side surface of hanging frame 47 through cord clip 67.
Flat plate-like metal plate 72 is provided on an upper surface of
second rotation detecting tool 64a, and second rotation detecting tool contact
73 is provided in the vicinity of metal plate 72. A lower surface of second
rotation detecting tool 64a is fixed to a top surface of ceiling fan body 44, and
second rotation detecting tool contact 73 is in conduction with a motor.
If flat plate-like magnet 70 on a lower surface of first rotation
detecting tool 63a and flat plate-like metal plate 72 on an upper surface of
second rotation detecting tool 64a are clung to each other through a magnetic
force, first rotation detecting tool contact 71 and second rotation detecting
tool contact 73 are connected to each other, and the motor is brought into
conduction with a power source.
A clinging force between magnet 70 and metal plate 72 through the
magnetic force is smaller than a rotation force of ceiling fan body 44 when it
rotates.
That is, in a state where fan blades 53 are abnormally mounted,
ceiling fan body 44 is operated, a large rocking motion of ceiling fan body 44
is generated, projection 58 is cut down or broken off, and ceiling fan body 44
rotates in some cases. In such a case, connection of abnormal-rotation
detector 57a is released by the magnetic force between magnet 70 and metal
plate 72 by the rotation force of ceiling fan body 44. Connection between
first rotation detecting tool contact 71 and second rotation detecting tool
contact 73 is also released, supply of power source to the motor is cut off, and
the operation of the motor can be stopped.
When the connection generated by the magnetic force is released by

the rotation force of the ceiling fan body 44 by connecting them using the
magnetic force, since the connecting force is only the magnetic force, the
connection force is stabilized and as a result, detection of rotation of ceiling
fan body 44 can be stabilized.
(Sixth Embodiment)
FIG. 21 is an appearance diagram showing a ceiling fan according to
a sixth embodiment of the invention. In the sixth embodiment of the
invention, only points which are different from the fourth embodiment are
described. Ceiling fan 250 of the sixth embodiment of the invention is
different from ceiling fan 230 of the fourth embodiment of the invention in an
abnormal-rotation detector. As shown in FIG. 21, abnormal-rotation
detector 57b includes first rotation detecting tool 63b and second rotation
detecting tool 64b.
That is, abnormal-rotation detector 57b stops energization to a motor
by displacement of a distance between first rotation detecting tool 63b and
second rotation detecting tool 64b. More specifically, first rotation detecting
tool 63b includes first detecting tool detecting portion 81, and shaft 49 is
inserted into an upper portion of first detecting tool mounting portion 81.
First detecting tool mounting portion 81 has a U-shaped cross section and
sandwiches a disk-like pulley 48. Curved plate-like first detecting tool
detecting portion 82 is provided on a lower portion of first rotation detecting
tool 63b so as to cover second rotation detecting tool 64b.
According to second rotation detecting tool 64b, push-on switch 86 is
fixed to a side surface of ball joint 61b at a position opposed to first detecting
tool detecting portion 82. Push-on switch 86 is energized in a contact state

between push-on switch 86 and first rotation detecting tool 63b, and push-on
switch 86 is not energized when push-on switch 86 is not in contact with first
rotation detecting tool 63b.
An example of second rotation detecting tool 64b is a limit switch.
Specifically, in a state where fan blades are abnormally mounted,
ceiling fan body 44 is operated, a large rocking motion is generated,
projection 58 is cut down or broken off, and ceiling fan body 44 rotates in
some cases. In such a case, push-on switch 86 of second rotation detecting
tool 64b is not in contact with first rotation detecting tool 63b, and
energization to the motor can be stopped.
Since the rotation of ceiling fan body 44 is recognized based on
contact or non-contact of push-on switch 86 in this manner, even if ceiling fan
body 44 rotates and push-on switch 86 is brought into non-contact state to
first rotation detecting tool 63b, charging portion is not exposed.
(Seventh Embodiment)
In a seventh embodiment of the invention, only points which are
different from the fourth embodiment are described. FIG. 22 is an
appearance diagram showing a ceiling fan according to a seventh
embodiment of the invention. Ceiling fan 260 of the seventh embodiment of
the invention is different from the ceiling fan 230 of the fourth embodiment
of the invention in an abnormal-rotation detector.
Abnormal-rotation detector 57c includes first rotation detecting tool
63c, second rotation detecting tool 64c and control device 80c. That is,
abnormal-rotation detector 57c sends a displacement of a distance between
first rotation detecting tool 63c and second rotation detecting tool 64c as an

electric signal by second rotation detecting tool 64c, and when the electric
signal exceeds a predetermined threshold value, control device 80c stops
energization to the motor.
Specifically, first rotation detecting tool 63c includes first detecting
tool detecting portion 81, and shaft 49 is inserted into an upper portion of
first detecting tool mounting portion 81. First detecting tool mounting
portion 81 has a U-shaped cross section and sandwiches a disk-like pulley 48.
Curved first detecting tool detecting portion 82 is provided on a lower portion
of first rotation detecting tool 63c so as to cover second rotation detecting tool
64c. Flat magnet 83 is fixed to an inner surface of first detecting tool
detecting portion 82. According to second rotation detecting tool 64c,
magnetic detecting portion 84 is fixed to a side surface of ball joint 61 at a
position opposed to flat magnet 83 of first detecting tool detecting portion 82.
Magnetic detecting portion 84 detects a magnetic force of magnet 83, and
sends a detection value to control device 80c as an electric signal.
Control device 80c is provided in ceiling fan body 44, receives the
detection value from magnetic detecting portion 84 as an electric signal.
When the detection value is equal to or lower than a predetermined
threshold value, control device 80c stops energization to the motor.
Specifically, in a state where the fan blades are abnormally mounted,
ceiling fan body 44 is operated, a large rocking motion is generated,
projection 58 is cut down or broken off, and ceiling fan body 44 rotates in
some cases. In such a case, magnetic detecting portion 84 of second rotation
detecting tool 64c detects a magnetic force of magnet 83 of first rotation
detecting tool 63c, and sends a detection value to control device 80c as an

electric signal. When the detection value is equal to or lower than the
predetermined threshold value, control device 80c can stop energization to
the motor.
Magnet 83 of first rotation detecting tool 63c and magnetic detecting
portion 84 of second rotation detecting tool 64c detect a magnetic force in a
non-contact state, and recognize that ceiling fan body 44 rotates by variation
in the magnetic force. Therefore, when ceiling fan body 44 rocks, it is
possible to prevent wear of magnet 83 which is abnormal-rotation detector
57c and magnetic detecting portion 84.
Control device 80c includes threshold value adjustor 85 which can
adjust the threshold value.
Since control device 80c includes threshold value adjustor 85, it is
possible to adjust the threshold value at an installing place.
(Eighth Embodiment)
In an eighth embodiment of the invention, only points which are
different from the fourth embodiment are described. FIG. 23 is an
appearance diagram showing a ceiling fan according to an eighth
embodiment of the invention. Ceiling fan 270 of the eighth embodiment of
the invention is different from ceiling fan 230 of the fourth embodiment of
the invention in an abnormal-rotation detector.
Abnormal-rotation detector 57d includes first rotation detecting tool
63d, second rotation detecting tool 64d and control device 80d.
Specifically, abnormal-rotation detector 57d sends a displacement of
a distance between first rotation detecting tool 63d and second rotation
detecting tool 64d as an electric signal by second rotation detecting tool 64d,

and when the electric signal exceeds a predetermined threshold value,
control device 80d stops energization to the motor.
More specifically, first rotation detecting tool 63d includes first
detecting tool mounting portion 81d, and shaft 49 is inserted into an upper
portion of first detecting tool mounting portion 81d. First detecting tool
mounting portion 81d has a U-shaped cross section and sandwiches a
disk-like pulley 48. Curved first detecting tool detecting portion 82d is
provided on a lower portion of first rotation detecting tool 63d so as to cover
second rotation detecting tool 64d. Flat reflector plate 90 is fixed to an
inner surface of first detecting tool detecting portion 82d. According to
second rotation detecting tool 64d, infrared emitter 91 and infrared receiver
92 are fixed to a side surface of ball joint 61d at a position opposed to flat
reflector plate 90 of first detecting tool detecting portion 82d. Infrared
emitter 91 emits infrared rays to reflector plate 90, infrared receiver 92
receives the infrared rays reflected from reflector plate 90, and its detection
value is sent to control device 80d as an electric signal.
Control device 80d is provided in ceiling fan body 44, receives the
detection value from infrared receiver 92 as the electric signal. When the
detection value is equal to or lower than a predetermined threshold value,
control device 80d stops energization to the motor.
That is, in a state where fan blades are abnormally mounted, ceiling
fan body 44 is operated, a large rocking motion is generated, projection 58 is
cut down or broken off, and ceiling fan body 44 rotates. In such a case,
infrared receiver 92 of second rotation detecting tool 64d detects infrared
rays from reflector plate 90 of first rotation detecting tool 63d, and sends its

detection value to control device 80d as an electric signal. When the
detection value is equal to or lower than the predetermined threshold value,
control device 80d can stop energization to the motor.
Thus, reflector plate 90 of first rotation detecting tool 63d and
infrared receiver 92 of second rotation detecting tool 64d are in a non-contact
state, and recognize that ceiling fan body 44 rotates by variation in infrared
rays. Therefore, when ceiling fan body 44 rocks, it is possible to prevent
infrared receiver 92 and reflector plate 90 which are abnormal-rotation
detector 57d from being worn.
INDUSTRIAL APPLICABILITY
The ceiling fan of the present invention can be utilized as a ceiling
fan for a home and for an office.

WE CLAIM :
1. A ceiling fan, comprising:
a motor which rotates a plurality of blades provided in a horizontal direction;
a shaft projecting from an upper portion of the motor, a pipe which is connected to an
upper end of the shaft and which hangs from a ceiling surface;
a connecting rod for connecting the pipe and the shaft with each other via through holes
formed in the pipe and the shaft, respectively;
a female screw which is threadedly engaged with the connecting rod;
a displacement-correspondence tool which is displaced or which detects a displacement
amount in correspondence with a relative positional displacement amount between the shaft and
the pipe: and
a power source control tool which controls energization to the motor in accordance with
the displacement of the displacement-correspondence tool or the detected displacement amount.
2. The ceiling fan according to claim 1, wherein the displacement-correspondence tool
can be divided into a shaft-side displacement-correspondence tool provided on a side of the shaft
and a pipe-side displacement-correspondence tool provided on a side of the pipe.
3. The ceiling fan according to claim 1, wherein the displacement-correspondence tool is
fixed with reference to an end of the pipe.

4. The ceiling fan according to claim 2, wherein the power source control tool can be
divided into a power source supplying tool provided on the pipe-side displacement-
correspondence tool and a power source receiving tool provided on the shaft-side displacement-
correspondence tool.
5. The ceiling fan according to claim 4, wherein the power source supplying tool and the
pipe-side displacement-correspondence tool are integrally formed as a female connector, and the
power source receiving tool and the shaft-side displacement-correspondence tool are integrally
formed as a male connector.
6. The ceiling fan according to claim 1, further comprising a flanged cap which covers a
tip end of the shaft, and which is fitted between the shaft and the pipe.
7. The ceiling fan according to claim 6, wherein material of the flanged cap is synthetic
resin.
8. The ceiling fan according to claim 6, wherein the flanged cap is integrally fixed to the
pipe, and they are formed as the pipe-side displacement-correspondence tool.
9. The ceiling fan according to claim 4 wherein a magnet is provided on one of the shaft-
side displacement-correspondence tool and the pipe-side displacement-correspondence tool, and
a metal plate is provided on the other one.
10. The ceiling fan according to claim 2, further comprising a controller which receives a
detection value from the displacement-correspondence tool as an electric signal, wherein when

the detection value exceeds a threshold value, the controller controls or stops energization to the
motor through the power source control tool.
11. The ceiling fan according to claim 10, further comprising a threshold value adjustor
on an input side of the controller so that the threshold value can be adjusted.
12. The ceiling fan according to claim 10 ,wherein a magnet is provided as the pipe-side
displacement-correspondence tool, a magnetic detecting tool is provided as the shaft-side
displacement-correspondence tool, and when the detection value of the magnetic detector
becomes equal to or lower than the threshold value, the controller stops the motor or reduces the
number of revolutions of the motor.
13. The ceiling fan according to claim 10, wherein a reflector plate is provided as the
pipe-side displacement-correspondence tool, an infrared emitter and an infrared receiver
connected to the controller are provided as the shaft-side displacement-correspondence tool, and
when a detection value of the infrared receiver is equal to or lower than a threshold value, the
controller stops the motor or reduces the number of revolutions of the motor.
14. The ceiling fan according to claim 1, further comprising an alarm for informing as to
an abnormal condition when the motor is stopped or the number of revolution is reduced,
wherein the alarm is provided near the displacement-correspondence tool.
15. A ceiling fan, comprising:
a connecting clamp fixed to a ceiling; and
a ceiling fan body hanging from the connecting clamp through a hanging device, wherein

the hanging device includes a first connecting portion which can be mounted on the
connecting clamp, and a second connecting portion provided on a lower portion of the first
connecting portion,
the ceiling fan body includes a motor which rotates a plurality of fan blades provided in a
horizontal direction, a shaft projecting from an upper portion of the motor, and a joint portion
fixed to an upper portion of the shaft,
the joint portion is movably mounted on the second connecting portion, and
the ceiling fan further includes an abnormal-rotation detector which detects a rotation of
the ceiling fan body and stops the motor when a body rotation-preventing device provided on the
joint portion and one of the first connecting portion and the second connecting portion is
released.
16. The ceiling fan according to claim 15, wherein the joint portion is a hemispherical
ball joint having a groove in its spherical surface, the second connecting portion is formed into a
bowl-like shape for movably holding the ball joint, and a notch through which the shaft can pass
and the body rotation-preventing device having a projection which can be inserted into the
groove are provided.
17. The ceiling fan according to claim 16, wherein the projection has a plate-like shape
having the groove and a gap in a state where the projection is inserted into the groove.
18. The ceiling fan according to claim 17, wherein an angle portion at which an inner
surface of the groove and an outer peripheral surface of the ball joint intersect with each other
comes into contact with an end surface of the projection when the ball joint rotates in a
horizontal direction.

19. The ceiling fan according to claim 16, wherein when the projection is cut down or
broken off, the abnormal-rotation detector stops the motor when the ceiling fan body rotates.
20. The ceiling fan according to claim 16, wherein the abnormal-rotation detector
includes a first rotation detecting tool and a second rotation detecting tool, the first rotation
detecting tool is fixed to the second connecting portion, the second rotation detecting tool is
fixed to the ceiling fan body, the first rotation detecting tool and the second rotation detecting
tool are connected to each other such that when they are separated from each other by a
predetermined distance when the ceiling fan body rotates, supply of power source to the motor is
stopped.
21. The ceiling fan according to claim 20, wherein the first rotation detecting tool is in
conduction with the power source, and the second rotation detecting tool is in conduction with
the motor.
22. The ceiling fan according to claim 20, wherein the first rotation detecting tool and the
second rotation detecting tool are connected to each other through a fitting force and are brought
into conduction with each other.
23. The ceiling fan according to claim 22, wherein the first rotation detecting tool is a
female connector and the second rotation detecting tool is a male connector.
24. The ceiling fan according to claim 23, wherein the male connector is fixed such that a
tip end thereof points obliquely upward.

25. The ceiling fan according to claim 20, wherein the first rotation detecting tool and the
second rotation detecting tool are connected to each other through a magnetic force and are
brought into conduction with each other.
26. The ceiling fan according to claim 25, wherein the first rotation detecting tool
includes a magnet and the second rotation detecting tool includes a metal plate.
27. The ceiling fan according to claim 20, wherein the second rotation detecting tool is a
push-on switch and the push-on switch comes into contact with the first rotation detecting tool,
whereby they are brought into conduction with each other.
28. The ceiling fan according to claim 20, further comprising a control device which
sends, as an electric signal by means of the second rotation detecting tool, a displacement of a
distance between the first rotation detecting tool and the second rotation detecting tool, and
which stops energization to the motor when the electric signal exceeds a predetermined threshold
value.
29. The ceiling fan according to claim 28, wherein the control device includes a threshold
value adjustor which can adjust the threshold value.
30. The ceiling fan according to claim 28, wherein the displacement of the distance is
detected by a displacement of a magnetic force by the first rotation detecting tool and the second
rotation detecting tool.

31. The ceiling fan according to claim 30, wherein the first rotation detecting tool
includes a magnet and the second rotation detecting tool includes a magnetic detecting portion.
32. The ceiling fan according to claim 28, wherein the displacement of the distance is
detected by a displacement of infrared rays by the first rotation detecting tool and the second
rotation detecting tool.
33.The ceiling fan according to claim 32, wherein the first rotation detecting tool includes
a reflector plate and the second rotation detecting tool includes an infrared emitter and an
infrared receiver.
34. A ceiling fan, comprising:
a connecting clamp fixed to a ceiling; and
a ceiling fan body hanging from the connecting clamp through a hanging device, wherein
the hanging device includes a first connecting portion which can be mounted on the
connecting clamp, and a second connecting portion provided on a lower portion of the first
connecting portion,
the ceiling fan body includes a motor which rotates a plurality of fan blades provided in a
horizontal direction, a shaft projecting from an upper portion of the motor, and a joint portion
fixed to an upper portion of the shaft,
the joint portion is movably mounted on the second connecting portion, and
the ceiling fan further includes an abnormal-rotation detector which detects a rotation of
the ceiling fan body and stops the motor when a body rotation-preventing device provided on the
joint portion and one of the first connecting portion and the second connecting portion is
released,

wherein the abnormal-rotation detector includes a first rotation detecting tool and a
second rotation detecting tool, the first rotation detecting tool is fixed to the second connecting
portion, the second rotation detecting tool is fixed to the ceiling fan body, the first rotation
detecting tool and the second rotation detecting tool are connected to each other such that when
they are separated from each other by a predetermined distance when the ceiling fan body
rotates, supply of power source to the motor is stopped,
wherein the second rotation detecting tool is a push-on switch and the push-on switch
comes into contact with the first rotation detecting tool, whereby they are brought into
conduction with each other.

A ceiling fan comprising a motor which rotates a plurality of blades
provided in a horizontal direction, a shaft projecting from an upper portion of
the motor, a pipe which is connected to an upper end of the shaft and which
hangs from a ceiling surface, a connecting rod for connecting the pipe and the
shaft with each other via through holes formed in the pipe and the shaft,
respectively, a female screw which is threadedly engaged with the connecting
rod, a displacement-correspondence tool which is displaced or which detects
a displacement amount in correspondence with a relative positional
displacement amount between the shaft and the pipe, and a power source
control tool which controls energization to the motor in accordance with the
displacement of the displacement-correspondence tool or the detected
displacement amount.