Title of Invention	AN IMPROVED HEAT DISSIPATABLE TWIN BLADE ELECTRIC FAN
Abstract	The invention relates to an improved heat dissipatable twin-blade electric fan comprising a motor (10) with a motor shaft (11) defining an axis (L) and having two end segments (111) that are axially opposite to each other; a pair of blade units (20) coupled respectively to and driven by said end segments (111) each of said blade units (20) comprising a hub (21), and a plurality of blades (22) that extend from said hub (21) and a pair of engaging units (50). Each of said end segments (111) is formed with an engaging protrusion (116) that defines a first engaging member (51), of the respective one of said engaging units (50 said hub (21) comprisisng a sleeve part (212) that is sleeved on the respective one of said end segments (111) and having a free end portion (213) formed with an engaging groove (215) which extends axially, which opens in a direction toward said motor (10), and which defines a second engaging member (52) of the respective one of said engaging units (50), and in that said engaging protrusion (116) of each of said end segments (111) extending into said engaging groove (215) in said free end portion (213) of said sleeve part (212), thereby securing said blade units (20) to said end segments (111) of said motor shaft (11), respectively.

Title of Invention

AN IMPROVED HEAT DISSIPATABLE TWIN BLADE ELECTRIC FAN

Abstract

The invention relates to an improved heat dissipatable twin-blade electric fan comprising a motor (10) with a motor shaft (11) defining an axis (L) and having two end segments (111) that are axially opposite to each other; a pair of blade units (20) coupled respectively to and driven by said end segments (111) each of said blade units (20) comprising a hub (21), and a plurality of blades (22) that extend from said hub (21) and a pair of engaging units (50). Each of said end segments (111) is formed with an engaging protrusion (116) that defines a first engaging member (51), of the respective one of said engaging units (50 said hub (21) comprisisng a sleeve part (212) that is sleeved on the respective one of said end segments (111) and having a free end portion (213) formed with an engaging groove (215) which extends axially, which opens in a direction toward said motor (10), and which defines a second engaging member (52) of the respective one of said engaging units (50), and in that said engaging protrusion (116) of each of said end segments (111) extending into said engaging groove (215) in said free end portion (213) of said sleeve part (212), thereby securing said blade units (20) to said end segments (111) of said motor shaft (11), respectively.

Full Text	The invention relates to an electric fan, more particularly to an electric fan with a pair of blade units . Referring to Figure 1, a conventional electric fan is shown to include a motor 1, a pair of blade units 2 respectively driven by the motor 1, and a stand unit 3 for supporting a bottom of the motor 1. When the motor 1 is actuated, the blade units 2 rotate simultaneously so as to generate two streams of air flow blowing in opposite directions relative to an axis so as to dissipate heat. Although the aforesaid electric fan is able to dissipate heat effectively, since only one motor 1 is used to simultaneously drive the two blade units 2, vibration tends to occur during rotation of the blade units 2 when the blade units 2 mounted on two end portions of a motor axle 101 of the motor 1 are unbalanced. Therefore, the object of the present invention is to provide an electric fan that is capable of overcoming the aforesaid drawback of the prior art. Accordingly, an electric fan of this invention comprises a motor, a pair of blade units, and a pair of engaging units. The motor has a motor shaft that defines an axis and that has two end segments which are axially opposite to each other. Each of the end segments has an engaging region. The engaging regions of the end segments of the motor shaft are disposed at angularly opposite positions relative to the axis. The blade units are coupled respectively to and are driven by the end segments of the motor shaft. Each of the blade units includes a hub that is sleeved on the respective one of the end segments, and a plurality of blades that extend from the hub. Each of the engaging units includes a first engaging member that is provided on the engaging region of a respective one of the end segments of the motor shaft, and a second engaging member that is provided on the hub of a respective one of the blade units and that engages the first engaging member, thereby securing the blade units to the end segments of the motor shaft, respectively. Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: Fig. 1 is a fragmentary partly sectional view of a conventional electric fan; Fig. 2 is a fragmentary partly sectional view of the first preferred embodiment of an electric fan according to the present invention; Fig. 3 is an exploded partly sectional view of an assembly of a motor and a pair of blade units of the first preferred embodiment; Fig. 4 is a sectional view taken along the line IV -IV in Fig. 2; Fig. 5 is an exploded partly sectional view of the second preferred embodiment of an electric fan according to the present invention; Fig. 6 is a fragmentary assembled partly sectional view of the second preferred embodiment; Fig.7 is a sectional view taken along the line VH -VII in Fig. 6; Fig. 8 is an exploded partly sectional view of the third preferred embodiment of an electric fan according to the present invention; Fig. 9 is a fragmentary assembled partly sectional view of the third preferred embodiment; and Fig.10 is a sectional view taken along the line X -X in Fig. 9. Before the present invention is described in greater detail with reference to the accompanying preferred embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure. Referring to Figures 2 to 4, the first preferred embodiment of an electric fan according to the present invention is shown to include a motor 10, a pair of blade units 20, and a pair of engaging units 50. The first preferred embodiment further includes a stand unit 40 for supporting the motor 10. The stand unit 40 includes a connecting rod 41 coupled to a bottom of the motor 10, and a stand 42 connected to the connecting rod 41. The motor 10 has a motor shaft 11 that defines an axis (L) and that has two end segments 111 axially opposite to each other. Each of the end segments 111 has an engaging region 113. The engaging regions 113 of the end segments 111 of the motor shaft 11 are disposed at angularly opposite positions relative to the axis (L) . The blade units 20 are coupled respectively to and are driven by the end segments 111 of the motor shaft 11. Each of the blade units 20 includes a hub 21 that is sleeved on a respective one of the end segments 111, and a plurality of blades 22 that extend from the hub 21. Each of the engaging units 50 includes a first engaging member 51 that is provided on the engaging region 113 of a respective one of the end segments 111 of the motor shaft 11, and a second engaging member 52 that is provided on the hub 21 of a respective one of the blade units 20 and that engages the first engaging member 51, thereby securing the blade units 20 to the end segments 111 of the motor shaft 11, respectively. In the first embodiment, each of the end segments 111 of the motor shaft 11 has a free end portion 112 with a non-circular cross-section. The free end portion 112 of each of the end segments 111 has a flat surface 116 that is disposed at the engaging region 113 and that defines the first engaging member 51 of the respective one of the engaging units 50. The hub 21 of each of the blade units 20 includes a sleeve part 212 that is sleeved on the respective one of the end segments 111 and that has a free end portion 213 with a non-circular cross-section. The free end portion 213 of the sleeve part 212 of the hub 21 of each of the blade units 20 has a flat surface 216 that defines the second engaging member 52 and that conforms to and that contacts the flat surface 116 of the free end portion 112 of the respective one of the end segments 111 of the motor shaft 11. Moreover, the hub 21 of each of the blade units 20 further includes a hub base 210 and an outer annular wall 214 that extends axially from a periphery of the hub base 210 and that surrounds the sleeve part 212, which extends axially from an inner portion of the hub base 210. The hub base 210 has an inner side 2101 and an outer side 2102 that is opposite to the inner side 2101. The sleeve part 212 of the hub 21 of each of the blade units 20 further has an open outer end 211 that is opposite to the free end portion 213 of the sleeve part 212 . Each of the end segments 111 of the motor shaft 11 has a threaded portion 114 that extends axially and outwardly through the open outer end 211 of the sleeve part 212 of the hub 21 of the respective blade unit 20. The electric fan further comprises a pair of screw nuts 30, each of which is disposed at the outer side 2102 of the hub base 210 of a respective blade unit 20and each of which engages threadedly the threaded portion 114 of a respective one of the end segments 111 of the motor shaft 11 so as to secure the blade units 20 to the end segments 111 of the motor shaft 11 after engagement between the first and second engaging members 51, 52 of the engaging units 50. After assembly, since the engaging units 50 are disposed at angularly opposite positions relative to the axis (L) , balance between the blade units 20 mounted respectively on the end segments 111 of the motor shaft 11 can be achieved, and vibration during actuation of the motor 10 can be reduced significantly. Referring to Figures 5, 6 and 7, the second preferred embodiment of this invention differs from the first preferred embodiment in that: each of the end segments 111 of the motor shaft 11 is formed with an engaging hole 116 that is disposed in the engaging region 113 and that defines the first engaging member 51 of the respective one of the engaging units 50 . The sleeve part 212 of the hub 21 of each blade unit 20 is formed with a threaded hole 215. The second engaging member 52 of each of the engaging units 50 is in the form of a screw 30 that engages threadedly and that extends through the threaded hole 215 in the sleeve part 212 of the hub 21 of the respective one of the blade units 20 and that engages the engaging hole 116 in the respective one of the end segments 111 so as to secure the blade units 20 to the end segments 111 of the motor shaft 11 after engagement between the first and second engaging members 51, 52 of the engaging units 50. Moreover, the sleeve part 212 of the hub 21 of each of the blade units 20 is formed with a blind hole 217 for insertion of the respective one of the end segments 111 of the motor shaft 11 Referring to Figures 8 to 10, the third preferred embodiment of this invention differs from the first preferred embodiment in that: the engaging region 113 of each end segment 111 is formed with at least one engaging protrusion 116 (in this embodiment, two engaging protrusions 116 are formed on the engaging region 113) that defines the first engaging member 51 of the respective one of the engaging units 50 . The sleeve part 212 of the hub 21 of each blade unit 20 has a free end portion 213 formed with an engaging groove 215 (in this embodiment, two engaging grooves 215 are formed in the free end portion 213 of the sleeve part 212) which extends axially, which opens in a direction toward the motor 10, and which defines the second engaging member 52 of the respective one of the engaging units 50. Each engaging protrusion 116 of each of the end segments 111 extends into the corresponding engaging groove 215 in the free end portion 213 of the sleeve part 212 of the hub 21 of the respective one of the blade units 20, as best shown in Figure 10 , thereby securing the blade units 20 to the end segments 111 of the motor shaft 11. By disposing the engaging units 50 at the angularly opposite positions relative to the axis (L) , the aforesaid drawback associated with the prior art can be alleviated. WE CLAIMS 1. An improved heat dissipatable twin blade electric fan, comprising (a) a motor (10) with a motor shaft (11) defining an axis (L) and having two end segments (ill) that are axially opposite to each other; (b) a pair of blade units (20) coupled respectively to and driven by said end segments (111), each of said blade units (20) comprising a hub (21), and a plurality of blades (22) that extend from said hub (21); and (c) a pair of engaging units (50); chararacterized in that each of said end segments (111) is formed with an engaging protrusion (116) that defines a first engaging member (51) of the respective one of said engaging units (50), said hub (21) comprising a sleeve part (212) that is sleeved on the respective one of said end segments (111) and having a free end portion (213) formed with an engaging groove (215) which extends axially, which opens in a direction toward said motor (10), and which defines a second engaging member (52) of the respective one of said engaging units (50), and in that said engaging protrusion (116) of each of said end segments (111) extending into said engaging groove (215) in said free end portion (213) of said sleeve part (212), thereby securing said blade units (20) to said end segments (111) of said motor shaft (11), respectively. 2- The electric fan as claimed in claim 1,wherein said free end portion (112) has a non-circular cross section, and having a flat surface (116) that defines said first engaging member (51), wherein said free end portion (213) has a non-circular cross-section, and having a flat surface (216) that defines said second engaging member (52) and that conforms to and that contacts said flat surface (116) of said free end portion (112) of the respective one of said end segments (111) of said motor shaft (11). 3. The electric fan as claimed in claim 1, wherein each of said end segments (111) is formed with an engaging hole (116) that defines said first engaging member (51), wherein said sleeve part (212) is formed with a threaded hole (215), and wherein said second engaging member (52) being configured as a screw (30) that engages threadedly and that extends through said threaded hole (215) in said sleeve part (212) and that engages said engaging hole (116) in the respective one of said end segments (111). 4. The electric fan as claimed in claim 1, wherein each of said end segments (111) having an engaging region (113), said engaging regions being disposed at angularly opposite positions relative to said axis (L). 5. The electric fan as claimed in claim 2, wherein said hub (21) comprises at hub base (210) and an outer angular wall (214) that extends axially from a periphery of said hub base (210) and that surrounds said sleeve part (212), said hub base (210) having an inner side (2101) and an outer side (2102) that is apposite to said inner side (2101), said sleeve part (212) having an open outer end (211) that is opposite to said free end portion (213), wherein each of said end segments (111) having a threaded portion (114) that extends axially and outwardly through said open outer end (211), and wherein said electric fan further comprising a pair of screw nuts (30), each of which is disposed at said outer side (2102) of said hub base (210), each of which en- gages threadedly said threaded portion (114) of a respective one of said end segments (111). ABSTRACT AN IMPROVED HEAT DISSIPATABLE TWIN-BLADE ELECTRIC FAN The invention relates to an improved heat dissipatable twin-blade electric fan comprising a motor (10) with a motor shaft (11) defining an axis (L) and having two end segments (111) that are axially opposite to each other; a pair of blade units (20) coupled respectively to and driven by said end segments (111) each of said blade units (20) comprising a hub (21), and a plurality of blades (22) that extend from said hub (21) and a pair of engaging units (50). Each of said end segments (111) is formed with an engaging protrusion (116) that defines a first engaging member (51), of the respective one of said engaging units (50 said hub (21) comprisisng a sleeve part (212) that is sleeved on the respective one of said end segments (111) and having a free end portion (213) formed with an engaging groove (215) which extends axially, which opens in a direction toward said motor (10), and which defines a second engaging member (52) of the respective one of said engaging units (50), and in that said engaging protrusion (116) of each of said end segments (111) extending into said engaging groove (215) in said free end portion (213) of said sleeve part (212), thereby securing said blade units (20) to said end segments (111) of said motor shaft (11), respectively.

Full Text

The invention relates to an electric fan, more
particularly to an electric fan with a pair of blade
units .
Referring to Figure 1, a conventional electric fan
is shown to include a motor 1, a pair of blade units
2 respectively driven by the motor 1, and a stand unit
3 for supporting a bottom of the motor 1. When the motor
1 is actuated, the blade units 2 rotate simultaneously
so as to generate two streams of air flow blowing in
opposite directions relative to an axis so as to
dissipate heat.
Although the aforesaid electric fan is able to
dissipate heat effectively, since only one motor 1 is
used to simultaneously drive the two blade units 2,
vibration tends to occur during rotation of the blade
units 2 when the blade units 2 mounted on two end portions
of a motor axle 101 of the motor 1 are unbalanced.
Therefore, the object of the present invention is
to provide an electric fan that is capable of overcoming
the aforesaid drawback of the prior art.
Accordingly, an electric fan of this invention
comprises a motor, a pair of blade units, and a pair
of engaging units.
The motor has a motor shaft that defines an axis and
that has two end segments which are axially opposite
to each other. Each of the end segments has an engaging

region. The engaging regions of the end segments of the
motor shaft are disposed at angularly opposite positions
relative to the axis.
The blade units are coupled respectively to and are
driven by the end segments of the motor shaft. Each of
the blade units includes a hub that is sleeved on the
respective one of the end segments, and a plurality of
blades that extend from the hub.
Each of the engaging units includes a first engaging
member that is provided on the engaging region of a
respective one of the end segments of the motor shaft,
and a second engaging member that is provided on the
hub of a respective one of the blade units and that engages
the first engaging member, thereby securing the blade
units to the end segments of the motor shaft,
respectively.
Other features and advantages of the present
invention will become apparent in the following detailed
description of the preferred embodiments with reference
to the accompanying drawings, of which:
Fig. 1 is a fragmentary partly sectional view of a
conventional electric fan;
Fig. 2 is a fragmentary partly sectional view of the
first preferred embodiment of an electric fan according
to the present invention;
Fig. 3 is an exploded partly sectional view of an
assembly of a motor and a pair of blade units of the

first preferred embodiment;
Fig. 4 is a sectional view taken along the line IV
-IV in Fig. 2;
Fig. 5 is an exploded partly sectional view of the
second preferred embodiment of an electric fan according
to the present invention;
Fig. 6 is a fragmentary assembled partly sectional
view of the second preferred embodiment;
Fig.7 is a sectional view taken along the line VH
-VII in Fig. 6;
Fig. 8 is an exploded partly sectional view of the
third preferred embodiment of an electric fan according
to the present invention;
Fig. 9 is a fragmentary assembled partly sectional
view of the third preferred embodiment; and
Fig.10 is a sectional view taken along the line X
-X in Fig. 9.
Before the present invention is described in greater
detail with reference to the accompanying preferred
embodiments, it should be noted herein that like elements
are denoted by the same reference numerals throughout
the disclosure.
Referring to Figures 2 to 4, the first preferred
embodiment of an electric fan according to the present
invention is shown to include a motor 10, a pair of blade

units 20, and a pair of engaging units 50. The first
preferred embodiment further includes a stand unit 40
for supporting the motor 10. The stand unit 40 includes
a connecting rod 41 coupled to a bottom of the motor
10, and a stand 42 connected to the connecting rod 41.
The motor 10 has a motor shaft 11 that defines an
axis (L) and that has two end segments 111 axially
opposite to each other. Each of the end segments 111
has an engaging region 113. The engaging regions 113
of the end segments 111 of the motor shaft 11 are disposed
at angularly opposite positions relative to the axis
(L) .
The blade units 20 are coupled respectively to and
are driven by the end segments 111 of the motor shaft
11. Each of the blade units 20 includes a hub 21 that
is sleeved on a respective one of the end segments 111,
and a plurality of blades 22 that extend from the hub
21.
Each of the engaging units 50 includes a first
engaging member 51 that is provided on the engaging region
113 of a respective one of the end segments 111 of the
motor shaft 11, and a second engaging member 52 that
is provided on the hub 21 of a respective one of the
blade units 20 and that engages the first engaging member
51, thereby securing the blade units 20 to the end
segments 111 of the motor shaft 11, respectively.
In the first embodiment, each of the end segments

111 of the motor shaft 11 has a free end portion 112
with a non-circular cross-section. The free end portion
112 of each of the end segments 111 has a flat surface
116 that is disposed at the engaging region 113 and that
defines the first engaging member 51 of the respective
one of the engaging units 50. The hub 21 of each of the
blade units 20 includes a sleeve part 212 that is sleeved
on the respective one of the end segments 111 and that
has a free end portion 213 with a non-circular
cross-section. The free end portion 213 of the sleeve
part 212 of the hub 21 of each of the blade units 20
has a flat surface 216 that defines the second engaging
member 52 and that conforms to and that contacts the
flat surface 116 of the free end portion 112 of the
respective one of the end segments 111 of the motor shaft
11. Moreover, the hub 21 of each of the blade units 20
further includes a hub base 210 and an outer annular
wall 214 that extends axially from a periphery of the
hub base 210 and that surrounds the sleeve part 212,
which extends axially from an inner portion of the hub
base 210. The hub base 210 has an inner side 2101 and
an outer side 2102 that is opposite to the inner side
2101. The sleeve part 212 of the hub 21 of each of the
blade units 20 further has an open outer end 211 that
is opposite to the free end portion 213 of the sleeve
part 212 . Each of the end segments 111 of the motor shaft
11 has a threaded portion 114 that extends axially and

outwardly through the open outer end 211 of the sleeve
part 212 of the hub 21 of the respective blade unit 20.
The electric fan further comprises a pair of screw nuts
30, each of which is disposed at the outer side 2102
of the hub base 210 of a respective blade unit 20and
each of which engages threadedly the threaded portion
114 of a respective one of the end segments 111 of the
motor shaft 11 so as to secure the blade units 20 to
the end segments 111 of the motor shaft 11 after
engagement between the first and second engaging members
51, 52 of the engaging units 50.
After assembly, since the engaging units 50 are
disposed at angularly opposite positions relative to
the axis (L) , balance between the blade units 20 mounted
respectively on the end segments 111 of the motor shaft
11 can be achieved, and vibration during actuation of
the motor 10 can be reduced significantly.
Referring to Figures 5, 6 and 7, the second preferred
embodiment of this invention differs from the first
preferred embodiment in that: each of the end segments
111 of the motor shaft 11 is formed with an engaging
hole 116 that is disposed in the engaging region 113
and that defines the first engaging member 51 of the
respective one of the engaging units 50 . The sleeve part
212 of the hub 21 of each blade unit 20 is formed with
a threaded hole 215. The second engaging member 52 of
each of the engaging units 50 is in the form of a screw

30 that engages threadedly and that extends through the
threaded hole 215 in the sleeve part 212 of the hub 21
of the respective one of the blade units 20 and that
engages the engaging hole 116 in the respective one of
the end segments 111 so as to secure the blade units
20 to the end segments 111 of the motor shaft 11 after
engagement between the first and second engaging members
51, 52 of the engaging units 50. Moreover, the sleeve
part 212 of the hub 21 of each of the blade units 20
is formed with a blind hole 217 for insertion of the
respective one of the end segments 111 of the motor shaft
11
Referring to Figures 8 to 10, the third preferred
embodiment of this invention differs from the first
preferred embodiment in that: the engaging region 113
of each end segment 111 is formed with at least one
engaging protrusion 116 (in this embodiment, two
engaging protrusions 116 are formed on the engaging
region 113) that defines the first engaging member 51
of the respective one of the engaging units 50 . The sleeve
part 212 of the hub 21 of each blade unit 20 has a free
end portion 213 formed with an engaging groove 215 (in
this embodiment, two engaging grooves 215 are formed
in the free end portion 213 of the sleeve part 212) which
extends axially, which opens in a direction toward the
motor 10, and which defines the second engaging member
52 of the respective one of the engaging units 50. Each

engaging protrusion 116 of each of the end segments 111
extends into the corresponding engaging groove 215 in
the free end portion 213 of the sleeve part 212 of the
hub 21 of the respective one of the blade units 20, as
best shown in Figure 10 , thereby securing the blade units
20 to the end segments 111 of the motor shaft 11.
By disposing the engaging units 50 at the angularly
opposite positions relative to the axis (L) , the
aforesaid drawback associated with the prior art can
be alleviated.

WE CLAIMS
1. An improved heat dissipatable twin blade electric fan,
comprising
(a) a motor (10) with a motor shaft (11) defining an axis
(L) and having two end segments (ill) that are axially
opposite to each other;
(b) a pair of blade units (20) coupled respectively to and
driven by said end segments (111), each of said blade units
(20) comprising a hub (21), and a plurality of blades (22)
that extend from said hub (21); and
(c) a pair of engaging units (50);
chararacterized in that each of said end segments (111)
is formed with an engaging protrusion (116) that defines a
first engaging member (51) of the respective one of said
engaging units (50), said hub (21) comprising a sleeve part
(212) that is sleeved on the respective one of said end
segments (111) and having a free end portion (213) formed with

an engaging groove (215) which extends axially, which opens
in a direction toward said motor (10), and which defines a
second engaging member (52) of the respective one of said
engaging units (50), and in that said engaging protrusion
(116) of each of said end segments (111) extending into said
engaging groove (215) in said free end portion (213) of said
sleeve part (212), thereby securing said blade units (20) to
said end segments (111) of said motor shaft (11),
respectively.
2- The electric fan as claimed in claim 1,wherein said free
end portion (112) has a non-circular cross section, and having
a flat surface (116) that defines said first engaging member
(51), wherein said free end portion (213) has a non-circular
cross-section, and having a flat surface (216) that defines

said second engaging member (52) and that conforms to and
that contacts said flat surface (116) of said free end
portion (112) of the respective one of said end segments
(111) of said motor shaft (11).
3. The electric fan as claimed in claim 1, wherein each
of said end segments (111) is formed with an engaging hole
(116) that defines said first engaging member (51), wherein
said sleeve part (212) is formed with a threaded hole (215),
and wherein said second engaging member (52) being
configured as a screw (30) that engages threadedly and that
extends through said threaded hole (215) in said sleeve part
(212) and that engages said engaging hole (116) in the
respective one of said end segments (111).
4. The electric fan as claimed in claim 1, wherein each of
said end segments (111) having an engaging region (113), said
engaging regions being disposed at angularly opposite
positions relative to said axis (L).

5. The electric fan as claimed in claim 2, wherein said
hub (21) comprises at hub base (210) and an outer angular
wall (214) that extends axially from a periphery of said hub
base (210) and that surrounds said sleeve part (212), said
hub base (210) having an inner side (2101) and an outer side
(2102) that is apposite to said inner side (2101),
said sleeve part (212) having an open outer end (211) that
is opposite to said free end portion (213), wherein each of
said end segments (111) having a threaded portion (114) that
extends axially and outwardly through said open outer end
(211), and wherein said electric fan further comprising a
pair of screw nuts (30), each of which is disposed at said
outer side (2102) of said hub base (210), each of which en-
gages threadedly said threaded portion (114) of a respective
one of said end segments (111).

ABSTRACT

AN IMPROVED HEAT DISSIPATABLE TWIN-BLADE
ELECTRIC FAN
The invention relates to an improved heat dissipatable twin-blade
electric fan comprising a motor (10) with a motor shaft (11)
defining an axis (L) and having two end segments (111) that are
axially opposite to each other; a pair of blade units (20)
coupled respectively to and driven by said end segments (111)
each of said blade units (20) comprising a hub (21), and a
plurality of blades (22) that extend from said hub (21) and a
pair of engaging units (50). Each of said end segments (111) is
formed with an engaging protrusion (116) that defines a first
engaging member (51), of the respective one of said engaging
units (50 said hub (21) comprisisng a sleeve part (212)
that is sleeved on the respective one of said end segments
(111) and having a free end portion (213) formed with an engaging
groove (215) which extends axially, which opens in a direction
toward said motor (10), and which defines a second engaging member
(52) of the respective one of said engaging units (50), and in

that said engaging protrusion (116) of each of said end segments
(111) extending into said engaging groove (215) in said free end
portion (213) of said sleeve part (212), thereby securing said
blade units (20) to said end segments (111) of said motor shaft
(11), respectively.

AN IMPROVED HEAT DISSIPATABLE TWIN BLADE ELECTRIC FAN

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