Electric clothes dryer

The heat source apparatus is positioned at an outer peripheral portion of a rotative drum and an upper portion of an inhale port member of a drum supporting member for supporting the rotative drum. The heater of the heat source apparatus is positioned at an axial direction of a rotational axis of the rotative drum within a heater case. The heat source apparatus is installed at an upper corner portion of an outer frame with a heater case supporting member. The heat source apparatus and the inhale port of the drum supporting member are communicated with a C-shaped form duct. The apparatus offers the advantage that the back flow and the accumulation of the lint etc. generated from the clothes in the rotative drum to the heat source apparatus can be prevented.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an electric clothes dryer and more 
particularly to an electric clothes dryer suitable for back flow 
prevention and accumulation prevention of the lint etc., which is 
generated from the clothes in a rotative drum, into a heater of a heat 
source apparatus side. 
2. Description of Prior Art 
In the conventional electric clothes dryer, a heat source apparatus having 
a heater has been installed around a plurality of hot air inhale ports 5 
of a rotative drum which receives the clothes therein. The heater is 
installed at a rear portion side of the rotative drum. The electric 
clothes dryer having the above stated heat source apparatus structure is 
disclosed in, for example, Japanese Patent Laid-Open No. 60900/85. 
According to the stirring motion of the clothes in the rotative drum, the 
ventilating air resistance at an exhaust air side of the rotative drum may 
increase, for example, due to the condition of the blinding phenomenon of 
a lint filter apparatus caused by no cleaning of the lint filter 
apparatus. The ventilating air, which flows commonly from the heat source 
apparatus side to the interior portion of the rotative drum side, however, 
flows backward from the interior portion of the rotative drum to the heat 
source apparatus side according to circumstances. 
Then the lint etc. generated from the clothes in the rotative drum gets 
into the heat source apparatus side. The lint etc. attach to a heater in 
the heat source apparatus and are burned thereon, as a result the dryer 
gives out a foul smell. In addition to this, after the lint etc. may be 
accumulated in the interior portion of the heat source apparatus, the lint 
etc. are burned by heat of the heater in the heat source apparatus. When 
things come to the worst, there is the extremely serious problem that the 
lint may burst into flames and the flames reach into the interior portion 
of the rotative drum and as a result the clothes in the rotative drum 
start to burn. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an electric clothes dryer 
wherein an electric clothes dryer having high safety can be obtained. 
Another object of the present invention is to provide an electric clothes 
dryer wherein an electric clothes dryer having high quality can be 
obtained. 
A further object of the present invention is to provide an electric clothes 
dryer wherein the lint etc. are prevented from flowing backward to the 
heat source apparatus, as a result of wind pressure caused by stirring the 
clothes in the rotative drum. 
A still further object of the present invention is to provide an electric 
clothes dryer wherein the lint etc. are prevented from getting into the 
heat source apparatus, as a result of wind pressure caused by stirring the 
clothes in the rotative drum. 
In accordance with the present invention, an electric clothes dryer 
comprises a main casing, a rotative drum being housed in the main casing 
for receiving the clothes, a heat source apparatus having a heater means 
being installed within the main casing for generating hot air, a motor 
being installed within the main casing and for driving the rotative drum, 
a lint filter apparatus being installed with the rotative drum. 
The heat source apparatus is positioned at an outer peripheral portion and 
an upper portion of the rotative drum. In particular, the heat source 
apparatus is positioned at an an upper portion of an inhale port member of 
a drum supporting member for supporting the rotative drum. 
The heat source apparatus for supplying hot air is positioned at the outer 
peripheral portion and the upper portion of the rotative drum. At the 
worst, the ventilating air resistance increases at the exhaust air side 
and the lint etc. are prevented from flowing backward and getting into the 
heat source apparatus, due to arisen from wind pressure caused by stirring 
the clothes in the rotative drum. 
According to the present invention, the prevention for the back flow and 
the accumulation of the lint etc. generated from the clothes in the 
rotative drum into the heat source apparatus can be realized, thereby the 
electric clothes dryer having high safety and high quality can be obtained 
.

DETAILED DESCRIPTION OF EMBODIMENT 
One embodiment of an electric clothes dryer of the present invention will 
be explained in accordance with drawings. The electric clothes dryer 
includes a main casing. The main casing is constituted by an outer frame 1 
and a rear cover 3 having a plurality of air inlet holes 3a therein. 
A rotative drum 4 is housed in this main casing and rotatively supported at 
a front portion by a ring shaped drum supporting member 14. The rotative 
drum 4 receives the clothes therein and is driven rotatively. The drum 
supporting member 14 is fixed on the outer frame 1 at a front side thereof 
and has a plurality of drum inhale ports 14a at an upper portion of the 
front side thereon. The drum inhale ports 14a of the drum supporting 
member 14 are each constituted generally as a punched opening in the metal 
member 14. 
A drum bearing member 9b is mounted on a drum supporting plate 9. The drum 
supporting plate 9 is fixed on the outer frame 1 and has blower inlet 
holes 9a thereon. The rotative drum 4 is rotatively supported by the drum 
supporting member 14 at the front side thereof and by a drum shaft 4a at 
the rear side thereof and further through the drum bearing a member 9b. 
The clothes are housed in the interior portion of the rotative drum 4 and 
the drying operation is carried out by the supply of hot air from a heat 
source apparatus 5. The heat source apparatus 5 is installed at one of the 
upper corner portions of the outer frame 1. The drum supporting member 14 
covers the front side of the rotative drum 4 and constitutes a part of a 
wall portion of a clothes receiving chamber. 
The rotative drum 4 has drum exhaust air holes 4b at a rear portion 
thereof. A lint filter apparatus 11 is installed at the front side of the 
drum exhaust air holes 4b of the rotative drum 4 so as to collect the lint 
etc. generated from the clothes in the rotative drum 4. 
A blower fan 7 is provided at the rear side of the drum exhaust air hole 4b 
so as to suck air from the interior portion of the rotative drum 4. The 
blower fan 7 is installed in a fan casing and supported by the drum shaft 
4a. The fan casing of the blower fan 7 is constituted by the drum 
supporting plate 9 and a casing 8. At the front side of the rotative drum 
4, a closing door 2 is mounted on the outer frame 1 of the main casing so 
as to cover the entrance for the clothes in the rotative drum 4. 
The heat source apparatus 5 has a coil shaped form heater 5a inside thereof 
and the heater 5a is provided within a cylindrical heater case 5c for 
receiving the heater 5a. The heat source apparatus 5 is mounted at an 
upper portion and an outer peripheral portion of the rotative drum 4 and 
is installed to the outer frame 1 of the main casing through two plate 
shaped form heater case supporting frames 5d. 
The heat source apparatus 5 and the drum inhale port 14a of the drum 
supporting member 14 are communicated by a C-shaped form duct 5b. The duct 
5b is fixed around the drum inhale port 14a of the drum supporting member 
14. One cylindrical end portion of the heater case 5c is inserted in one 
cylindrical end portion of the duct 5b with faucet joint condition. 
The heater 5a of the heat source apparatus 5 is positioned so as to extend 
in an axial direction of that is, parallel to a rotational axis of the 
rotative drum 4. Namely, the heater 5a of the heat source apparatus 5 is 
arranged above and at an outer cylindrical portion or a frame peripheral 
portion of the rotative drum 4 along substantially the longitudinal 
direction thereof. 
The passage for air circulation is formed in turn between the air inlet 
holes 3a of the rear cover 3, the heater 5a of the heat source apparatus 
5, the duct 5b, the drum inhale ports 14a of the drum supporting member 
14, the interior portion of the rotative drum 4, the lint filter apparatus 
11, the drum exhaust air hole 4b of the rotative drum 4, the blower inlet 
hole 9a of the drum supporting plate 9, the blower fan 7 and the exhaust 
air port 8a of the casing 8. 
A motor 6 is installed at a bottom portion of the outer frame 1 of the main 
casing via a motor base 6a. A fan pulley 6a is mounted on one end of a 
shaft of the motor 6. The fan pulley 6b drives the blower fan 7 via a fan 
belt 12. A drum pulley 6c is mounted on at another end portion of the 
shaft of the motor 6. The drum pulley 6c drives the rotative drum 4 via a 
drum belt 13. A controlling apparatus 10 controls the operation of the 
motor 6 and the heater 5a of the heat source apparatus 5 and determines 
the operating program of the electric clothes dryer. 
The operation and effects of the electric clothes dryer having the heat 
source apparatus of the above embodiment of the present invention, are 
explained below. 
When the cleaning of the lint filter apparatus 11 of the electric clothes 
dryer is not performed or forgotten, the blinding condition occurs at the 
lint filter apparatus 11. Then air flow by the blower fan 7 is restrained 
by the blinding condition of the lint filter apparatus 11, however, the 
rotative drum 4 continues to rotate. 
At that occasion, by the blast of the stirred clothes in the rotative drum 
4, the dust such as lint etc. generated from the clothes in the rotative 
drum 4 begins to flow backward to the drum inhale port 14a side of the 
drum supporting member 14 from the interior portion of the rotative drum 
4. The drum inhale port 14a of the drum supporting member 14 constitutes 
an opening portion for communicating the electric clothes dryer main body 
and the air outside. 
However, the wind pressure caused by the blast of the stirred clothes in 
the rotative drum 4 of the electric clothes dryer does not apply force 
against the dust so as to reach the drum inhale ports 14a of the drum 
supporting member 14, because of the pressure loss caused in the duct 5b 
at elbow portions thereof and because the drum inhale port 14a of the drum 
supporting member 14 is positioned at the upper portion thereof. Thereby 
dust back flow to the heat source apparatus 5 can be prevented. 
At the worst, even if the wind pressure caused by the blast of the stirred 
clothes is more than above stated generated value, the dust back flow into 
the heater 5a of the heat source apparatus 5 can be prevented, because the 
heat source apparatus 5 is positioned at a higher upper portion position 
than the installing position of the drum inlet ports 14a of the drum 
supporting member 14 and further because of the special structure of the 
drum inhale ports 14a of the drum supporting member 14. 
As the drum inhale port 14a of the drum supporting member 14 is constituted 
generally as punched opening in a metal form and such an opening structure 
has a large resistance to air, the dust circulation to the heat source 
apparatus 5 side can be prevented against the wind pressure which is in 
relation to the degree of the blast for the clothes. 
By the installing position of the heater 5a and the heater case 5c of the 
heat source apparatus 5 with the heater case supporting frame 5d at the 
outer peripheral portion and the upper portion to the rotative drum 4, the 
installing position of the heat source apparatus 5 with the drum inhale 
port 14a of the drum supporting member 14 is placed at the 180.degree. 
reversed position with the C-shaped duct 5b having two elbow portions. 
Thereby the dust such as lint etc. back flow to the heat source apparatus 
5 from the interior portion of the rotative drum 4 can be prevented 
effectively. 
When the heater 5a and the heater case 5c of the heat source apparatus 5 is 
positioned at the outer peripheral portion of the rotative drum 4, the 
heat source apparatus 5 is positioned in general at an axial direction 
with the rotational axis of the rotative drum 4 as shown in the above 
embodiment of the present invention. 
Then the outer cylindrical portion or the frame portion of the rotative 
drum 4 is warmed up by radiant heat generated by the heat source apparatus 
5. Further the incidental effect can be obtained, that is, the amount of 
radiant heat portion by the heat source apparatus 5, which was considered 
as useless one before, can be utilized effectively so as to dry the 
clothes in the rotative drum 4 of the electric clothes dryer. 
Besides, from the standpoint of the effective use of the radiant heat 
generated from the heat source apparatus 5, the heat source apparatus 5 
may be positioned at the outer peripheral portion and moreover at the 
lower portion of the rotative drum 4 with the drum inhale port 14a, which 
is positioned at the lower portion of the drum supporting member 14, for 
the purpose of applying convection heat. 
However, the above stated installing position of the heat source apparatus 
5 at the lower portion in the rotative drum 4 runs counter to the 
settlement of the problems considering the back flow prevention and the 
accumulation prevention of the lint etc. with the heat source apparatus 5 
because the lint etc. accumulate easily at the lower portion of the 
rotative drum 4 of the electric clothes dryer.