Washing machine

A washing machine comprises a drum rotating device, a water supplying device, a draining device, a sensing device for sensing excessive foam generated beyond a permissible amount in an outer tub of the washing machine in the washing operation, and a control device for controlling the drum rotating device, the water supplying device and the draining device. In this washing machine, the sensing device would sense the abnormal foaming in the washing operation and inputs a foam sensing signal to the control device. Then, the control device forces the water supplying device to supply water in the tub and/or the draining device to drain the tub so as to settle the abnormal foaming.

BACKGROUND OF THE INVENTION 
(i) Field of the Invention 
The present invention relates to a washing machine and, more particularly, 
it relates to a washing machine which comprises an outer tub supported in 
a frame, and a drum rotatably held about a horizontal supporting shaft in 
the tub and formed with many bores in its peripheral wall and which is 
capable of sensing foam generated beyond a permissible amount in the tub 
in washing the laundry. 
(ii) Description of the Prior Art 
In a conventional drum washing machine, since the rotation of a drum 
violently agitates washing water including detergent, foam is generated in 
a tub. When the foam is excessively generated, it impedes the drum from 
rotating, and the foam remaining in the tub pollutes rinsing water. 
Japanese Unexamined Patent Application No. 118195/1984 discloses a drum 
washing machine. The drum washing machine comprises an outer tub supported 
in a frame, a drum rotatably held about a horizontal supporting shaft in 
the tub and formed with many bores in its peripheral wall, rotating means 
for rotating the drum and sensing means for sensing foam generated beyond 
a permissible amount in the tub in washing the laundry. 
The sensing means senses the foaming in washing the laundry and raises an 
alarm to urge the user to dilute washing water. 
A float is used for the sensing means. When the float is raised by the 
foam, a sensing switch works. 
However, in this prior art embodiment, the user must laboriously manage the 
defoaming whenever foam is excessively generated. In this case, the 
defoaming requires only diluting washing water, and thus water in the tub 
increases. As a result, although the rotation of the drum causes the 
laundry to beat the wall of the drum, the laundry float in the increased 
washing water, and hence the desired result of the beating is not 
obtained. 
Although the float is used for the sensing means, the float requires 
considerable foam to rise. Thus, foaming must be in a fairly advanced 
stage to be sensed. 
It is known that a pair of electrodes can be used for the sensing means 
utilizing the conduction between those electrodes. However, contrary to 
using the float, the electrodes become conductive even with a small 
quantity of foam or water, so that the use of them leads to a large error. 
Additionally, the electrodes are easily soiled, and therefore the accuracy 
in sensing is reduced as time elapses. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a washing 
machine comprising an outer tub supported in a frame, water supplying 
means for supplying water to the tub, draining means for draining the tub, 
a drum rotatably supported about a horizontal supporting shaft in the tub 
and formed with many bores in its peripheral wall, drum rotating means for 
rotating the drum, sensing means for sensing foam generated beyond a 
permissible amount in the tub in washing the laundry, and means for 
settling foaming in response to a foam sensing signal from the sensing 
means. 
In short, the present invention provides a drum washing machine 
characterized by including the sensing means for sensing foam generated 
beyond the permissible amount in the tub; and control means for 
controlling the drum rotating means, the water supplying means and the 
draining means. When the foam sensing signal is received from the sensing 
means in washing the laundry, the control means acts to instruct the 
supplying means and/or the draining means to supply water to the tub 
and/or drain the tub. 
In this way, defoaming can be assuredly done without much labor. Further, 
the result which is obtained by the laundry beating the wall of the drum 
is not lost. 
Preferably in order to effectively defoam, in addition to practicing the 
above-mentioned water supply and/or drainage, the drum is controlled, for 
example, to temporarily stop and to rotate at low speed, and means for 
heating water and means for blowing air are provided. 
As the foam sensing means, for example, sensing means which comprises an 
overflow chamber formed in the wall of the outer tub, communicating with a 
drain pipe and having a pair of electrodes in the overflow chamber is used 
instead of the above-mentioned prior art float. 
The order of supplying water to the tub and draining the tub is arbitrary, 
and both the supply and drainage may be carried out simultaneously. 
"Water supply and/or drainage" in this invention means supplying water to 
the tub by the above-mentioned supplying means and/or draining the tub by 
the above-mentioned draining means. Also, "washing" means cleaning 
processes such as washing, rinsing, hydroextracting and drying in bloc. A 
concept of "a washing machine" herein includes a machine practicing all or 
one of the above-mentioned cleaning processes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A washing machine according to the present invention includes a 
microcomputer which is placed in a given position and is used as control 
means for controlling the drum rotating means, the water supplying means 
and the draining means. 
The washing machine also includes sensing means for sensing foam generated 
beyond a permissible amount in an outer tub. The sensing means preferably 
includes an overflow chamber provided in the wall of the tub and 
communicating with a drain pipe, and a pair of electrodes placed in the 
overflow chamber and sensing the foaming in washing the laundry. In this 
way, a sensing unit for exclusive use can be omitted, and the 
manufacturing cost can be reduced. In addition to that, the electrodes do 
not so easily become conductive because of water, and this ensures 
defoaming. 
The overflow chamber has a partition for separating the electrodes from an 
overflow inlet of the overflow chamber, and thus the overflow chamber has 
a double-cell structure where the partition divides a room into two. 
Preferably, the cells communicate to each other. In this way, since the 
electrodes are separated from the overflow inlet, the electrodes do not so 
easily become conductive because of a slight foam, so that mistakes in 
sensing can be prevented. 
The electrodes are preferably rod-shaped, and preferably held hanging down 
in the overflow chamber. In this way, the moisture on the electrodes can 
easily run down the rod, and the surface of the electrodes is kept drained 
off. Thus, the electrodes is prevented from corroding. 
A partition plate is preferably provided between the electrodes to separate 
them from each other, so that the electrodes do not become tangled in 
lint. Even if the electrodes are deformed, they would not come into 
contact with each other. 
Preferably, an inlet pipe is provided in a position where the electrodes 
are held to introduce water from the position to the overflow chamber. In 
this way, since water supplied from the roots of the electrodes cleans the 
electrodes, the accuracy in sensing can be kept well. 
Preferably, the overflow chamber has an overflow outlet for water 
projecting upward and an aperture formed below the overflow outlet and 
communicating to the outer tub. In this way, the water used for cleaning 
the electrodes can be collected without waste, and this effectively saves 
water. 
The control means preferably acts to instruct the water supplying means to 
supply water and increase the amount of the water in the tub. Water is 
supplied when abnormal foaming is sensed to defoam and dilute washing 
water. Thus, the foaming can assuredly be settled without much labor. 
The control means preferably acts to instruct the water supplying means and 
the draining means to supply water and increase the amount of the water in 
the tub and to drain the tub by a predetermined amount of water. Since the 
supplied water is useful in settling the foaming and keeping the washing 
water at an adequate water level after the drainage, the result which is 
obtained by the laundry beating the wall of the drum is not lost even 
after foaming is settled. 
The control means may act to instruct the drum rotating means to stepwise 
increase operating time per unit time, so that the foaming is inhibited, 
and labor and time spent for defoaming can be somewhat omitted. 
The washing machine according to the present invention may include the 
blowing means for blowing air, to which the control means acts to instruct 
the blowing means to blow air in supplying water to the tub and/or 
draining the tub, so that the supplied water defoams and the air blows the 
foam. Thus, the blowing means produces considerable effect in defoaming. 
The washing machine according to the present invention may include the 
water heating means for rising the temperature of the washing water in the 
outer tub. The control means acts to instruct the water supplying means 
and/or the draining means to supply water in the tub and/or to drain the 
tub in a predetermined time from the beginning of the washing, and then it 
acts to instruct the water heating means to rise the temperature of the 
washing water. In the case of washing the laundry with hot water, the 
foaming has to be sensed and settled before the washing water is heated, 
so as to prevent supplied water from lowering the temperature of the hot 
water. 
The washing machine according to the present invention may preferably 
include alarming means for causing a user to realize that the foaming has 
been settled by supplying water in the tub and/or draining the tub. The 
control means preferably acts to instruct the alarming means to give 
warning in response to a stored signal which means the foaming has been 
settled, after the washing including washing, rinsing, hydroextracting, or 
drying operation is completed. From the experience at this time, the user 
will regulate the amount of detergent next time. 
The control means may preferably include means for estimating the degree of 
the foaming based upon the length of period from a certain point of time 
to a point of time when the foam sensing signal is received from the 
sensing means. The control means acts to instruct the water supplying 
means and/or the draining means to regulate the water to be supplied 
and/or to be discharged in accordance with the estimation of the 
estimating means. In this case, required and sufficient amount of supplied 
and/or discharged water can be selected to avoid wasting time in 
defoaming. 
The control means may act to instruct the drum rotating means to 
temporarily stop the drum in supplying water. In this case, the drum is 
stopped in settling the foaming, and hence foaming proceeds no more. 
The control means may act to instruct the drum rotating means to rotate the 
drum at low speed in supplying water. In this case, since the drum rotates 
at low speed in settling the foaming, the supplied water reaches every 
inch of the drum, and hence considerable effect in defoaming can be 
produced. 
The control means may act to instruct the water supplying means to supply 
water intermittently, so that the supplied water can be saved. 
According to another aspect of the present invention, the drum washing 
machine is characterized in that a fluid balancer which is relatively 
heavy compared with other components is placed at only one end of the drum 
body, and the relatively heavy drum rotating means is placed close to the 
other end of the drum body in the outer bottom portion of the outer tub. 
In short, the fluid balancer is positioned close to the one end of the 
outer tub, and the drum rotating means is positioned close to the other 
end of the outer tub. 
In this way, the fluid balancer and the drum rotating means are balanced in 
weight to control the inclination of the outer tub elastically supported, 
and the drum can be rotated without difficulty. 
More specifically, the washing machine of the present invention producing 
the aforementioned effects can overcome the disadvantage in a washing 
machine disclosed in Examined Japanese Patnet Application No. 2998/1980; 
there can be solved the problem that the outer tub inclines because its 
rear portion is heavier than its front portion, and consequently the drum 
does not rotate smoothly. 
Embodiments of the present invention will now be described in conjunction 
with the accompanying drawings. "Abnormal foaming" herein means the 
foaming generated beyond a permissible amount in an outer tub of a washing 
machine in washing the laundry. 
Referring to FIGS. 1 to 6, a drum washing machine of the present invention 
comprises a frame 1 made of sheet iron, an outer tub 2 made of synthetic 
resin and having a shape like a horizontal shaft drum. The drum has a 
horizontal supporting face 3 in its bottom portion and positioned in the 
frame 1. An iron mounting plate 4 is fixed to the horizontal supporting 
face 3. 
The outer tub 2 is elastically suspended from the frame 1 with four upper 
supporting members 5 fixed to four corners of the upper portion of the 
frame 1. Each of the upper supporting members 5 is comprised of a 
supporter 6, an upper hook 6a formed in one end of the supporter 6 for 
catching hold of the four corners of the upper portion of the frame 1, a 
lower spring receiver 7 attached to the other end of the supporter 6 and 
formed with an aperture 7a in its center portion and with a concave 
portion 7b in its outer peripheral portion, a supporting rod 9 fitted in 
the aperture 7a of the lower spring receiver 7 for catching at its one end 
hold of a holder 8 provided at each of four corners in the upper portion 
of the outer tub 1, an upper spring receiver 10 seizing the other end of 
the supporting rod 9, and a spring A 11 extending between the lower spring 
receiver 7 and the concave portion 7b. 
The supporter 6 is made of a single thick wire bent as shown in FIG. 9; a 
coil 6b is formed at the end opposite to the upper hook 6a, and the lower 
spring receiver 7 is screwed into the coil 6b. 
The lower spring receiver 7 is made with an upper member 12 made of resin 
and having the concave portion 7b and a lower member 13 made of elastic 
rubber and having the aperture 7a, adhering to each other. A grease pocket 
14 is formed in the inner surface of the aperture 7a to smoothly slide the 
supporting rod 9. 
The vibration of the outer tub 2 is absorbed due to the extension and 
contraction of the spring A 11 of the upper supporting member 5 and the 
slide resistance between the supporting rod 9 and the aperture 7a. 
A lower supporting member 15 is placed between the mounting plate 4 of the 
outer tub 2 and each of the four corners of the bottom 1a of the frame 1 
to elastically bear the outer tub 2. The lower supporting member 15 is 
made of a spring B 16 extended between the mounting plate 4 and the frame 
1, and an elastic cylinder 17 surrounding the spring B 16. The vibration 
of the outer tub 2 is absorbed due to the extension and contraction of the 
spring B 16 and the frictional resistance between the spring B 16 and the 
cylinder 17. The elastic cylinder 17 prevents the spring B 16 from 
buckling down. 
A tube 18 is a rectangular hollow body formed integral with the outer tube 
2 and extending upward from the upper portion of the outer tub 2. The tube 
18 defines an opening B 19 for taking in and out the laundry in the upper 
portion of the outer tub 2. The upper edge of the tube 18 is intended to 
reach almost the same level as a virtual upper circumferential plane 2a of 
the outer tub 2. A mounting boss 20 is also integrally formed along the 
upper edge of the tube 18 in a position at almost the same level as the 
virtual upper circumferential plane 2a. A packing explained below is fixed 
to the mounting boss 20 with screws. 
An upper panel 21 made of synthetic resin is fixed on the upper edge of the 
frame 1. The upper panel 21 has units swelling out therefrom; an operating 
unit 21a containing electronic parts in its front end and has a housing 
unit 21b housing water supplying device in its rear end. The upper panel 
21 has a rectangular opening A 22 for taking in and out the laundry in its 
center portion. Various operating keys 23 are disposed in the upper face 
of the operating unit 21a. A rubber packing 24 has a shape like bellows 
and its lower end 24a is fixed to the mounting boss 20 of the tube 18 with 
screws 25. 
A gasket 26 made of synthetic resin is comprised of a vertical wall 26a fit 
into the opening A 22, a horizontal wall 26b put on a rim 22a of the 
opening A 22 from the upper part and a claw 26c bulging inward from the 
center of the inner front of the vertical wall 26a. The upper end 24b of 
the rubber packing 24 is put between the rim 22a of the opening A 22 and 
the gasket 26, and the horizontal wall 26b and the rubber packing 24 are 
fixed to the rim 22a with screws 27. The upper end of the rubber packing 
24 is folded into a flap 28 which covers the screws 27 fastening the 
rubber packing 24 and the rim 22a. 
A safety cover 29 is pivotably held by the rear edge of the opening A 22 to 
cover the opening A 22. The safety cover 29 is provided with a claw 31 at 
its bottom face of the front center. The claw 31 is always pressed upward 
by a spring 30 and interlocked with the claw 26c of the gasket 26 from the 
lower part when the safety cover 29 is closed. An end 31a of the claw 31 
is pushed up by the pressing of the spring 30 to release the interlock 
between the claws 31 and 26c, so that the safety cover 29 can be opened. 
When the safety cover 29 is closed, the lower face of the safety cover 29 
is contact with the upper face of the flap 28. 
A lid 32 is pivotably held before the housing unit 21b of the upper panel 
21 to lie over the safety cover 29. A supporting arm 33 is formed 
projecting from the rear end of the lid 32 into the housing unit 21b. A 
torsion coil spring 34 is fixed between the supporting arm 33 and a 
supporting rib 35 in the housing unit 21b. Due to the coil spring 34, the 
lid 32 opens and closes as if an articulation works well. 
The rear wall 2b of the outer tub 2 is individually manufactured. The rear 
wall 2b is bonded to the remaining part of the tub 2 after a drum 
explained later is put in position from the rear opening of the tub 2. A 
cylinder 36 is formed in the center portion of the rear wall 2b. An air 
duct A 37 is integrally formed with the outer surface of the rear wall 2b. 
A wall 37a extends from the upper center of the air duct A 37 to the 
cylinder 36 and covers the cylinder 36. A rear bearing 38 for the drum is 
fixed to the wall 37a close to the cylinder 36. In the upper part of the 
air duct A 37, a heater casing 39 is formed, and a sheathed heater A 40 is 
placed therein. An iron plate 41 encloses the heater A 40 to prevent the 
fire originated in dust or the like from spreading to resin material. 
An overflow outlet 42 provided at the level corresponding to a half of the 
height of the rear wall 2b. An overflow pipe 43 serves as an overflow 
chamber to conduct water from the overflow outlet 42. A pair of electrodes 
44 serving as foam sensing means are placed in the overflow pipe 43. An 
air trap 45 is formed in the lower portion of the rear wall 2b and is 
connected to a water level sensor 46 provided in the housing unit 21b 
through a pressure hose 47. 
A drain outlet 48 is provided in the bottom of the outer tub 2, and a valve 
case 49 is also provided having three connecting pipes 50, 51, 52. The 
connecting pipe 50 is connected to the drain outlet 48. A drain valve 53 
serving as a part of draining means is provided in the valve case 49 to 
open and close the connecting pipe 50. A drain valve motor 54 serving as a 
part of the draining means is provided to open and close the drain valve 
53. Wire 55 connected to the drain valve 53 is rolled by the rotation of 
the drain valve motor 54 to open the drain valve 53. The force applied by 
a spring (not shown) restores the drain valve 53 to the closed state by 
cutting off the rotation force of the drain motor 54. 
An overflow hose 56 connects the overflow pipe 43 to the connecting pipe 52 
of the valve case 49. A drain hose 57 serving as a part of the draining 
means is connected to the connecting pipe 51 of the valve case 49, and has 
its end drawn out of the machine. A dehumidifying pipe 58 made of 
synthetic resin is vertically provided in the rear corner portion of the 
frame 1. A fan device 59 which is comprised of a fan and a fan motor 60 to 
serve as air blowing means is provided in the upper end of the 
dehumidifying pipe 58. The fan device 59 has its inlet lead to the 
dehumidifying pipe 58 and its outlet connected to the heater casing 39 
through an air blowing duct B 61 having a shape like bellows. The 
dehumidifying pipe 58 whose two lower ends each communicate with the 
overflow hose 56 and the drain hose 57 through a drain pipe 63 and a 
circulating duct 62 having a shape like bellows, respectively. 
A twin water supply electromagnetic valve 64 serving as a part of water 
supply means is provided in the housing unit 21b. One of the water supply 
valves, A 64a, is connected to an opening 66 provided in the tube 18 
through a inlet hose A 65 serving as a part of water supply means, and the 
other of the water supply valves, B 64b, is connected to the upper portion 
of the dehumidifying pipe 58 through an inlet hose B 67 serving as a part 
of the water supply means. A sheathed heater B 68 serving as temperature 
rising means is provided in the inner bottom portion of the outer tub 2, 
and a front bearing 68a for the drum is fixed to the center portion of a 
front wall 2c of the outer tub 2. 
The horizontal shaft drum 69 made of synthetic resin is rotatably supported 
in the outer tub 2 and used for washing, hydroextracting and drying. The 
drum 69 is comprised of a cylindrical body 70 leaving its rear side open, 
a fluid balancer 71 attached near the rear end of the body 70, and a rear 
panel 72 fixed after the balancer 71. 
A baffle 73 is a projection having a triangular section and is provided at 
a position of every 120.degree. along the inner peripheral surface of the 
body 70. The body 70 is provided with many perforations 74 around the 
surface, and is also provided with many horizontal ribs 75 along the inner 
peripheral surface of the body 70. The horizontal ribs 75 are also formed 
in the upper face of the baffles 73. The rib 75 on the baffle 73 is 
particularly put in position so that the angle .theta..sub.1 comes to be 
an obtuse angle and the angle .theta..sub.2 comes to be an acute angle, as 
shown in FIG. 17. The performations 74 are gradually widened from the 
inner portion to the outer portion as shown in FIG. 18 (another example as 
shown in FIG. 19 may be used). 
The fluid balancer 71 is a hollow annular member containing a certain 
quantity of salt water. A plurality of resistance plates 76 are set inside 
the fluid balancer 71 at intervals of every 30.degree. from the rear side 
to the front. A distance between each of the resistance plates 76 and 
either of the inner and outer interior surfaces is under 5 mm, and the 
distance in the outer part is smaller than that in the inner part. As 
shown in FIG. 16, a plurality of concave portions 77 are provided along 
the front inner peripheral surface of the balancer 71, and work as the 
resistance plates 76 do. 
An inlet 78 is formed projecting in the center portion of the rear panel 72 
to fit into the cylinder 36, and a supporting shaft 79 is fixed at the 
center of the inlet 78. An axial flow fan 80 serving also as a filter is 
integrally formed in the inlet 78. 
Then, as shown in FIG. 16, the balancer 71 is fitted into the body 70, and 
fixed to the rear end of the body 70 with screws at a position where it 
comes in contact with the ends of the baffles 73. The rear panel 72 is put 
on the rear side of the balancer 71 and fixed thereto with screws, and 
this makes the drum 69 perfect. In this way, the balancer 71 is used as a 
wall between the end of the body 70 and the rear panel 72, and hence, 
resin material can be saved by an amount corresponding to an interval A 
(see FIG. 2) between the body 70 and the rear panel 72. 
A supporting shaft 81 is fixed in the center portion of a front panel 82 of 
the body 70. A filter mounting portion 83 is formed in the inner surface 
of the front panel 82 and closer to the outer circumference thereof. The 
filter mounting portion 83 is provided with a concave portion 84 close to 
its outer circumference portion, a projection 85 close to the center 
portion and a rib 86, which is triangular in section, at the center 
portion. 
A filter unit 87 is composed of an elongated frame 88 and a net 89 attached 
to the frame 88. The frame 88 is provided with a claw 90 at its one end 
and another claw 91 at the other end. The claw 90 engages with the concave 
portion 84 and the claw 91 elastically engages with the projection 85. In 
order to complete the attachment of the filter unit 87, the frame 88 
pivots on the fulcrum where the claw 90 just engages with the concave 
portion 84, and then the claw 91 engages with the projection 85. In order 
to remove the filter unit 87, these steps may be done in the reverse 
order. 
A rectangular opening C 92 for taking clothes in and out is defined in the 
body 70, extending along the circumferential surface of the body 70. The 
opening C is almost as large as the opening B 19. Slide grooves 93, 94 are 
formed at the body 70 before and after the opening C 92 very close 
thereto. A slide cover 95 individually manufactured is attached to the 
slide groove 93. A claw 96 is formed projecting upward from one side of 
the body 70 close to the opening C 92, and a contact rib 97 is formed 
projecting upward from the other side. The opening C 92 is positioned just 
above the filter mounting portion 83. 
A lid 98 made of synthetic resin is placed at the opening C 92 and is 
slidably held in the slide grooves 93, 94. A pull 99 is pivotably held at 
an end of a side of the lid 98. The pull 99 is provided with a claw 100 
which interlocks with the claw 96, at one end, and a concave portion 101 
at the other end, and a spring 102 always urges the pull 99 in order that 
the claw 100 interlocks with the claw 96. 
A rib 103 is formed at an end of the opposite side of the lid 98, 
projecting downward. Reservoir concaves 104, 104 are integrally formed in 
the center portion of the upper surface of the lid 98. The reservoir 
concaves 104, 104 reserve washing soap, bleaching agent, softening agent, 
etc. for later use. It is desirable that a plurality of the reservoir 
concaves 104, 104 be provided for various kinds of treatment agent. 
In order to open the lid 98, the concave portion 101 is pressed down to 
release the interlock between the claws 96 and 100 and the lid 98 is slid 
to its opening position. On the other hand, when the lid 98 is slid to its 
closed position, the claw 100 is pressed up along the inclined face of the 
claw 96 until it automatically interlocks with the claw 96. 
The front and rear drum bearing 68a, 38 rotatably support the supporting 
shafts 79, 81 holding the drum 69. The supporting shaft 81 projects from 
the front wall of the outer tub 2. A drive pulley 105 is fixed to the 
supporting shaft 81. 
A washer motor 106 as drum rotating means is fixed to the mounting plate 4 
by a mounting member 107, and a small pulley A 108 is fixed to a motor 
shaft. A hydroextractor motor 109 is fixed to the mounting plate 4 by a 
mounting member 110, and a large pulley A 111, a small pulley B and a 
brake drum 113 are fixed to a motor shaft 109a. The small and large 
pulleys A 108 and A 111, and the small pulley B 112 and the drive pulley 
105 are connected to each other through belts 114 and 115, respectively. 
The washer motor 106 and the hydroextractor motor 109 are disposed closest 
to the forefront of the outer tub 2. 
With the washing machine having a structure as stated above, in washing the 
laundry, the washer motor 106 repeatedly rotates the drum 69 alternately 
in opposite directions at low speed so that the laundry carried up in the 
drum 69 falls down and beats against the bottom of the drum 69, resulting 
in a good washing effect. Further, in hydroextracting, the hydroextractor 
motor 109 rotates the drum 69 in one direction at high speed, so that 
centrifugal action of the spinning drum extracts water from the laundry 
within the drum 69. 
In the washing machine of this embodiment, although the balancer 71, the 
washer motor 106 and the hydroextractor motor 109 are relatively heavy, 
they are disposed to be well-balanced by positioning the balancer 71 close 
to the rear end of the outer tub 2 and positioning the washer motor 106 
and the hydroextractor motor 109 close to the front end thereof, so that 
the outer tub 2 does not easily incline. 
FIG. 67 shows the results of measurement of the vibration of the drum 69 
when a hydroextracting operation is carried out with weight balance 
varied. A horizontal axis L shows the distance from the middle point 
between the balancer 71 and the middle point of the motors 106, 109 to the 
vertical center line of the drum 69. A vertical axis W is the maximum 
amplitude of the outer tub 2 during the hydroextracting operation. 
Namely, as the middle point between the balancer 71 and the middle point of 
the motors 106, 109 is deviated more largely from the center of the outer 
tub 2, they get more ill-balanced and the drum 69 comes to rotate 
unstably. This results in the outer tub 2 vibrating largely during the 
hydroextracting operation. 
A brake lever 116 is pivotably supported by the mounting member 110 of the 
hydroextractor motor 109. The brake lever 116 has a brake shoe 117. When 
the lid 32 is opened, a spring not shown urges the brake shoe 117 so that 
the brake shoe 117 comes in pressure contact with the brake drum 113. A 
wire 118 has its one end connected to the brake lever 116 and the other 
end connected to the torsion coil spring 34. A tube 119 serves as a 
guiding and protecting member for the wire 118. 
When the lid 32 is closed, a connecting portion 34a of the torsion coil 
spring 34 is displaced upward and pulls the wire 118. The brake lever 116 
is rotated to leave the brake shoe 117 from the brake drum 113. When the 
lid 32 is opened, the connecting portion 34a of the torsion coil spring 34 
is displaced downward and slackens the wire 118. Then, the brake shoe 117 
is pressed to come in contact with the brake drum 113, and thus the 
hydroextractor motor 109 is braked. 
A magnet 120 is attached to the drive pulley 105. A reed switch 121 is 
placed closest to and opposed to the magnet 120 of the outer tub 2. The 
reed switch 121 is closed when the magnet 120 is set close to it by the 
rotation of the drive pulley 105, and opened when the magnet 120 is set 
away from it. Rotation position detecting means for the drum 69 is 
composed of the magnet 120 and the reed switch 121, though explained 
below. The reed switch 121 is placed in a position above and perpendicular 
to the shaft line of the drum 69. 
A first negative characteristic thermistor 122 is placed close to the 
bottom of the outer tub 2, and is a component of a water temperature 
sensing circuit explained below. A second negative characteristic 
thermistor 123 is placed at the opening for insertion of a heater in the 
heater casing 39. A third negative characteristic thermistor 124 is placed 
within the overflow pipe 43. The second and third thermistors 123, 124 are 
composed of a drying completion sensing circuit explained below. 
Now, an exemplary circuit of the washing machine of the present invention 
will be described in conjuction with FIG. 23. 
A micro computer 125 (for example, LC 6523 manufactured by Sanyo Electric 
Co., Ltd.) controls the rotation of the drum 69, water supply and 
drainage, and is composed, as is well known, of a CPU 126, a RAM 127 as 
storage means, a ROM 128, a timer 129, a system bus 130 and input/output 
ports 131 to 136, as shown in FIG. 22. 
The CPU 126 is composed of a control unit 137 and an operating unit 138. 
The control unit 137 fetches and executes instructions. The operating unit 
138 performs operating processes such as binary addition, logical 
operation, addition and subtraction, and comparison for data received from 
an input device and a memory in response to a control signal from the 
control unit 138. The RAM 127 stores data related to devices. The ROM 128 
stores in advance means of operating the devices, setting conditions for 
judgment, rules for processing various information, etc. 
The microcomputer 125 receives signals from an input key circuit 139 
composed of a group of various operating keys 23, the water level sensor 
46, an safety switch 140 switching on or off correspondingly to the 
opening and closing of the lid 32, the reed switch 121, a washer motor 
current detecting circuit 141, a hydroextractor motor current detecting 
circuit 142, a reference pulse generating circuit 143, a water temperature 
sensing circuit 144 and a drying completion sensing circuit 145. 
The microcomputer 125 makes the washer motor 106 rotate in the forward and 
reverse directions based upon information. The microcomputer 125 further 
sends drive signals to the hydroextractor motor 109, the water supply 
electromagnetic valve 64a, the water supply electromagnetic valve 64b, the 
drain valve motor 54, the fan motor 60, the heater A 40, the heater B 68, 
a buzzering circuit 146 as alarming means, and an LED driving circuit 147 
as warning means. The microcomputer 125 and the loads are connected 
through bi-directional thyristors 148 to 156. The microcomputer 125 
outputs signals to turn on and off the bi-directional thyristors 148 to 
156. 
The water level sensor 46 functions as follows: First, it detects the 
change in the water level in the outer tub 2 as the change in the pressure 
within the air trap 45, and then move a magnetic member in a coil in 
accordance with the detected pressure. Thus, it detects the change in the 
water level as the change in inductance of the coil. Further, it detects 
the change in the inductance as the change in oscillation frequency and 
inputs the detection results to the microcomputer 125. The microcomputer 
125 detects the water level within the outer tub 2 successively and in a 
wide scope based upon the change in the oscillation frequency. 
The washer motor current detecting circuit 141 is composed of a current 
transformer A 157 detecting current existing in the washer motor 106, a 
circuit 158 rectifying the detected current, smoothing it and converting 
it into direct current voltage V.sub.A, and a comparator A 159 comparing 
the voltage V.sub.A with the reference voltage V.sub.1 to output a warning 
signal A to the microcomputer 125 when V.sub.A &gt;V.sub.1. 
The hydroextractor motor current detecting circuit 142 is composed of a 
current transformer B 160 detecting current existing in the hydroextractor 
motor 109, a circuit 161 rectifying the detected current, smoothing it and 
converting it to direct current voltage V.sub.B and a comparator B 162 
comparing the voltage V.sub.B with the reference voltage V.sub.2 to output 
a warning signal B to the microcomputer 125 when V.sub.B &gt;V.sub.2. 
The reference pulse generating circuit 143 is composed of a transistor 163, 
and various resistances and capacitors. The circuit 143 receives at its 
input terminal a full-wave rectifying signal of the voltage at a secondary 
side of a transformer (not shown) and inputs pulses synchronized with zero 
cross points of commercial supply voltage to the microcomputer 125, as 
shown in FIG. 25. 
The microcomputer 125 controls the bi-directional thyristors 148, 149, 150 
of the washer motor 106 and the hydroextractor motor 109 based upon the 
reference pulse to appropriately turn on and off with a unit of a half 
cycle of alternate current supply voltage. Specifically, as shown in FIG. 
24, when the bi-directional thyristors 148, 149, 150 are turned on n times 
out of m times with a unit of a half cycle of the supply voltage, the 
number of revolutions of the motors is about n/m compared to the case 
where the thyristors are successively kept turned on. Hereinafter, this 
control system is referred to as n/m pulse cut control. 
Further, half-wave is applied to the motors through 1/2 pulse cut control 
so as to brake the motors. Hereinafter, this braking system is referred to 
as direct current brake. 
The water temperature sensing circuit 144 inputs voltage V.sub.4 varied by 
reference voltage V.sub.3 and a resistance value of the first thermistor 
122 to an operational amplifier 164, and outputs a warning signal C to the 
microcomputer 125 from the operational amplifier 164 at the point of time 
when V.sub.4 &gt;V.sub.3. 
Although the voltage condition is initially set to satisfy V.sub.3 
&gt;V.sub.4, the first thermistor 122 decreases in the resistance value as 
the temperature of the washing water rises, and accordingly the value of 
the voltage V.sub.4 increases. V.sub.4 &gt;V.sub.3 is satisfied at the point 
of time when the temperature of the washing water reaches a critical 
temperature (about 70.degree. C.), and then abnormality is sensed. 
The drying completion sensing circuit 145 inputs voltage V.sub.5 varied by 
a resistance value of the second thermistor 123 and voltage V.sub.6 varied 
by a resistance value of the third thermistor 124 to an operational 
amplifier 165, and outputs a completion signal D to the microcomputer 125 
from the operational amplifier 165 at the point of time when V.sub.6 
&gt;V.sub.5 is satisfied. 
Although the voltage condition is initially set to satisfy V.sub.5 
&gt;V.sub.6, the resistance value of the third termistor 124 is increasingly 
reduced as the drying operation proceeds, and the voltage condition 
satisfies V.sub.6 &gt;V.sub.5 when the laundry is completely dehumidified. 
Then, the microcomputer 125 receives a signal from the operational 
amplifier 165 and defines that the drying is completed. 
The operation based upon the above-mentioned system will be explained in 
conjunction with FIGS. 34 to 44. 
According to this embodiment, the water level within the outer tub 2 during 
the washing process can be set with three levels (High, Middle, Low). The 
reversal cycle of the drum 69 during the washing and rinsing process can 
be set with three levels (Strong: ON for 15 seconds--OFF for 3 seconds, 
Standard: ON for 9 seconds--OFF for 3 seconds, Weak: ON for 6 seconds--OFF 
for 3 seconds), and the degree of hydroextraction can be set with two 
levels (Standard: successively turning on, Weak: 2/3 pulse cut control). 
The water level during the rinsing process is set at "High" level in 
advance, and the reversal cycle of the drum during the drying process is 
set at ON for 10 seconds--OFF for 2 seconds in advance. 
Operating the keys enables the user to choose between a standard course 
where a sequence of processes of washing, rinsing, hydroextracting and 
drying are performed respectively on standard operating conditions (i.e., 
period of time, water level, reversal cycle of the drum, degree of 
hydroextraction) and a shortened course where a period of time spent for 
each processe is cut down. The operating conditions in each course can be 
varied by the key operation (this process can be omitted if the required 
period is set zero). 
Then, the microcomputer 125 controls the operations of the loads one after 
another in accordance with the preset course. 
Referring to FIG. 34, the microcomputer 125, immediately after powered on, 
automatically sets the standard course (S-1). Then, the user might make a 
change in conditions, if any (S-2) When water level is set "Low" and the 
drum reversal cycle is set "Weak", generally there may be a small quantity 
of laundry or the laundry may be delicate, and hence the degree of 
hydroextraction comes to automatically be set "Weak" (S-3). Then, the 
course starts when a start key for the course is operated (S-4). 
The operation will be described for every process in practicing the 
standard course. Although not shown in flow charts, counters are 
independently provided to count a period of time for each process, a 
period of time for he rotation of a motor, a period of time for a pause, 
etc. They are reset after they has counted a specified period of time. 
Washing Process 
As shown in FIG. 35, in the washing process, water is first supplied in the 
tub 2 to a predetermined water level, and simultaneously the heater B 68 
is turned on to heat the water in the tub 2 (S-10 to S-13). Then, the 
washer motor 106 rotates reversely for a predetermined period of time in a 
reverse rotation cycle where it rotates forward for 9 seconds--stops for 3 
seconds--rotates reversely for 9 seconds--stops for 3 seconds (S-14 to 
S-21). 
The drum 69 rotates reversely due to the rotation of the washer motor 106. 
Washing treatment agent (washing agent or bleaching agent when the washing 
operation is performed) reserved in the reservoir concave 104 is put in 
and solves in the washing water. In the drum 69, the laundry is carried up 
by the baffle 73 and falls down to beat against the bottom of the drum 69. 
Also, the laundry rubs against the lateral ribs 75 and the concave 
portions 77, and thus the washing is effectively done. 
According to this embodiment, direct current braking is performed to the 
washer motor 106 and the hydroextractor motor 109 for 2 seconds 
synchronizing with the pause of the washing motor 106. This results in the 
drum 69 stopping abruptly, and the reaction causes the laundry to beat 
against the inner wall of the drum 69. Thus the washing effect is further 
increased. 
Assuming now that the ratio of the small pulley A 108 to the large pulley A 
111 is 1 to 3 and that the ratio of the small pulley B 112 to the drive 
pulley 105 is 1 to 3, the ratio of the small pulley A 108 to the drive 
pulley 105 comes to be 1 to 9. Consequently, the torque necessary for the 
washer motor 106 to rotate the drum 69 may be 1/3 of the torque necessary 
for the hydroextractor motor 109 to rotate the drum 105. 
This applies to the braking force to each of the motors. If equivalent 
braking forces are applied, the washer motor 106 is effectively braked 
rather than the hydroextractor motor 109 is. This is effectuated for the 
case where the starting torque of the washer motor 106 and that of the 
hydroextractor motor 109 are almost the same (in this embodiment, the 
starting torque of the hydroextractor motor 109 is about 1.2 times larger 
than that of the washer motor 106). If a hydroextractor motor of large 
starting torque is used, the braking force effectively works for the 
hydroextractor motor. However, the large starting torque requires large 
electric power and leads to cost increase, and thus the motor of such 
large torque causes the disadvantage in practical use. 
Thus, it is effective to brake the washer motor 106 through the direct 
current braking. In this embodiment, both the motors 106 and 109 are 
braked through direct current braking to obtain further braking effect. In 
the explanation below, also, the direct current braking means brake both 
the motors. 
During the reversal rotation of the drum 69, the washing water pass from a 
gap 166 between the frame 88 and the filter mounting portion 83 to the net 
89, and lint in the water is trapped by the net 89. 
After a specified time elapses, the heater B 68 and the washer motor 106 
are turned off (S-23) (S-24), and the washing water is discharged (S-25). 
In this washing process, the abnormal foaming managing program in FIG. 36 
is carried out as a sub-program at the same time. It begins to count 
T.sub.A seconds (S-26) simultaneously with the turn-on of the washer motor 
106. At this time, foam is produced excessively due to the reversal 
rotation of the drum 69 depending upon the concentration of the washing 
agent. The foam comes in the overflow pipe 43 from the overflow outlet 42 
to make the electrodes 44, 44 conductive. 
Then, the microcomputer 125 counts the time T.sub.A until the electrodes 
44, 44 are kept conductive for successive 2 seconds. The time T.sub.A and 
the reference value stored in the ROM 128 are compared (S-27) (S-28) 
(S-29). When 0.ltoreq.T.sub.A .ltoreq.10, it is estimated the degree of 
the abnormal foaming is extremely high, and a value T.sub.C in the next 
water resupplying program is set 30 seconds (S-30). Also, when 10&lt;T.sub.A 
.ltoreq.20, the value T.sub.C is set 20 seconds (S-31); when 20&lt;T.sub.A 
.ltoreq.30, the value T.sub.C is set 10 seconds; and when T.sub.A &gt;30, the 
value T.sub.C is set 5 seconds (S-33), respectively. The reason why 
electrodes 44, 44 are kept conductive for two seconds successively is to 
distinguish from the conduction for a shorter period of time due to the 
overflowing water. 
In the water re-supplying program, T.sub.A is cleared (S-34) to temporarily 
stop the washing operation (S-35). After discharging water for the set 
period T.sub.C seconds (S-37) to (S-39), water is supplied again to the 
predetermined water level (S-40) to (S-43), and the operation starts 
again. 
Namely, in this abnormal foaming managing program, the washing water is 
diluted in accordance with the degree of the foaming, if the foam is 
abnormally produced, because the higher concentration of the washing agent 
causes the higher the degree of foaming. 
Rinsing Process 
The operations in the rinsing process are similar to those in the washing 
process shown at (S-10) to (S-25). 
Hydroextracting Process 
When the hydroextracting operation is performed on an overload condition 
such that too much laundry is put in the drum or cloth catches the drum 
shaft, the motors may lock or generate abnormal heat and is damaged by the 
heat. 
Then, as shown in FIG. 37, the load sensing program 1 (S-50) (explained 
later) where the overload condition is sensed is carried out. If there is 
nothing abnormal, the washer motor 106 rotates for five minutes in the 
reversal cycle of forward rotation for 3 seconds--pause for 2 
seconds--reverse rotation for 3 seconds--pause for 2 seconds. 
Simultaneously, the direct current braking is carried out while the washer 
motor 106 pauses (S-51) to (S-58). This five-minutes reversal operation 
untangles the laundry within the drum 69 and puts it uniformly in the drum 
69. 
Then, the hydroextracting operation is fully performed. Before that, the 
load sensing program 2 (S-59) (explained later) where the overload 
condition is sensed is carried out. If there is sensed nothing abnormal, 
the washer motor 106 is, in addition to the hydroextractor motor 109, 
rotated forward simultaneously to smoothly start the hydroextractor motor 
109 (S-60) (S-61). Ten seconds after, the hydroextractor motor 109 alone 
is kept rotated (S-62). The draining valve 53 is opened (S-63), the heater 
A (40) is turned on (S-64), and the hydroextracting operation is performed 
only for a set period (S-65) (S-66) (S-67). 
In this hydroextracting operation, the axial flow fan 80 acts to absorb hot 
air heated by the heater A 40 and introduces it into the drum 69. This 
enhances the efficiency of dehumidification. 
As shown in FIG. 38, in the load sensing program 1, the washer motor 106 is 
rotated forward for 2 seconds (S-68) (S-69), and then a condition of a 
signal received from the washer motor current detecting circuit 141 is 
searched (S-70). If the warning signal A is not found, it is decided that 
the drum 69 is not overloaded, and the step (S-51) and the followings are 
carried out. 
When the warning signal A is found, instead of the reversal operation of 
the washer motor 106 at (S-51) to (S-58), both the washer motor 106 and 
the hydroextractor motor 109 rotate intermittently in the similar rotation 
cycle for five minutes (S-71) to (S-82). This allots the overload which 
should have been applied to the washer motor 106 alone to both the washer 
motor 106 and the hydroextractor motor 109. At (S-72) (S-73), the warning 
signal A or B is still found, the operation is immediately stopped (S-83), 
and a warning of abnormality is given (by buzzing or lighting up and out 
all the LEDs) (S-84). 
As another example of (S-50) to (S-58), the hydroextractor motor 109 may 
intermittently be turned on and off to untangle the laundry. In such a 
case, as shown in FIG. 39, the hydroextractor motor 109 is kept ON for two 
seconds (S-85) (S-86), and then a condition of a signal received from the 
hydroextractor motor current detecting circuit 142 is searched. If the 
warning signal B is found, the hydroextractor motor 109 is turned off 
(S-88), and the step (S-68) and the followings are carried out. If the 
warning signal B is not found, it is judged that the drum 69 is not 
overloaded, and the hydroextractor motor 109 is intermittently rotated for 
five minutes in a cycle of ON for 3 seconds--OFF for 2 seconds (including 
the direct current braking) (S-89) to (S-95). 
Then, in the load sensing program 2, as shown in FIG. 40, the washer motor 
106 is rotated for two seconds (S-96) (S-97), and then a condition of a 
signal received from the washer motor current detecting circuit 141 is 
searched (S-98). If the warning signal A is not found, the step (S-60) and 
the followings are carried out. If the warning signal A is found, the 
hydroextractor motor 109 is further driven (S-990). After the condition is 
improved, the step (S-60) and the followings are carried out. If the 
condition cannot be improved, the operation is immediately stopped, and a 
warning of abnormality is given (S-100) to (S-103). 
As another example of the (S-96) to (S-103), the hydroextractor motor 109 
alone may start the hydroextracting operation. In such a case, as shown in 
FIG. 41, the hydroextracting motor 109 is kept ON for two seconds (S-104) 
(S-105), and then a condition of a signal received from the 
hydroextracting motor current detecting circuit 142 is searched (S-106). 
If no abnormality is found, the step (S-63) and the followings are 
directly carried out, and if any, the hydroextractor motor 109 is 
temporarily turned off (S-107), and then the step (S-96) and the 
followings are carried out. 
Drying Process 
As shown in FIG. 42(a), this process includes four steps; intermittent 
turning on for 5 minutes and then off for 5 minutes (S-110), a first 
drying program (S-111), a second drying program (S-112) and a third drying 
program (S-113). 
According to the first drying program (S-111), the fan motor 60, the heater 
A 40 and the water supplying valve B 64b are driven respectively, as shown 
in FIG. 42(b) (S-114) (S-115) (S-116). Additionally, the washer motor 106 
is rotated for 90 seconds in the reversal cycle of forward rotation for 10 
seconds--pause for 2 seconds (including the direct current 
braking)--reverse rotation for 10 seconds--pause for 2 seconds (including 
the direct current braking) (S-118) to (S-125). 
This enables the hot air heated by the heater A (40) to pass through the 
air duct A 37 and enter the drum 69 from the inlet 78. In this way, the 
hot air exchanges heat with the laundry within the drum 69. The air after 
the heat exchange is discharged through the circulating path of the 
overflow outlet 42--the overflow pipe 43--the overflow hose 56--the 
circulating duct 62--the dehumidifying pipe 58--air duct B 61 and 
introduced to the heater casing 39 again. 
In this circulating path, water from the water supplying valve B 64b drops 
along the inner peripheral wall surface of the dehumidifying pipe 58. As a 
result, the discharged air passing through the dehumidifying pipe 58 is 
cooled by the water and dehumidified. The humidity removed from the air is 
discharged together with the water out of the machine from the drain pipe 
63 and the drain hose 57. 
After 90 seconds has elapsed, the fan motor 60, the heater A 40, the water 
supplying valve B 64b and the washer motor 106 are turned off, and the 
second drying program (S-112) is carried out (S-126) to (S-129). 
According to the second drying program (S-112), the heater B 68 is turned 
on and off for eighty seconds in the cycle of ON for 10 seconds and OFF 
for 10 seconds, as shown in FIG. 42(c) (S-130) to (S-134). In this way, 
the laundry cling to the inner surface of the drum 69 can be dehumidified 
through the bores 74. As a result, the laundry can easily come off from 
the drum 69. 
Then, the third drying program (S-113) shown in FIG. 42(d) is carried out. 
The program steps (S-135) to (S-149) are similar to those in the first 
drying program (S-115) to (S-129). However, the third drying program 
(S-113) is completed when the completion of the drying is sensed based on 
a signal from the drying completion sensing circuit 145 at (S-144). 
The drain valve motor 54 is intermittently driven (S-110) during the drying 
process. While the drain valve 53 is opened, air is discharged from the 
drain outlet 48. Thus, the flow of the drying air is changed in the drum 
69, and the laundry can be uniformly dehumidified. 
The second drying program can be carried out simultaneously with the first 
and third drying program. 
FIG. 43 shows a water temperature regulating program (S-150) which is 
carried out during the washing and rinsing process. When the washing water 
heated by the heater B 68 reaches a critical temperature, the laundry is 
damaged or the user is scaleded. To prevent that, the microcomputer 125 
ignores the main program and forces the heater B 68 to turn off for five 
minutes when it receives a warning signal C from the water temperature 
sensing circuit 144 (S-151) to (S-156). 
FIG. 44 shows a drum stopping program (S-160) for stopping the drum 69 
always in position. 
When the course is completed, when the lid 32 is kept open or when the 
course is interrupted by the operation of a temporary stop key (not 
shown), the drum 69 should be stopped with the lid 98 facing the opening B 
19 for taking out the laundry easily. 
In such a case, the microcomputer 125 counts a period T (seconds) which is 
an interval between the ON and OFF of the reed switch 121 (S-161). When 
T&gt;3 (seconds) is satisfied, the drum 69 is rotated through the 1/3 pulse 
cut control (S-162) (S-163). Then, immediately after the reed switch 121 
turns on, the washer motor 106 is turned off while the direct current 
braking is performed for three seconds (S-164) to (S-168). This causes the 
drum 69 to immediately stop. As stated above, since the lid 98 is 
correlated to the reed switch 121, the lid 98 is necessarily stopped at 
the position above the reed switch 121. 
When the lid 32 is left open, the brake shoe 117 is pressed against the 
brake drum 113 to come in contact with it. However, since the 1/3 pulse 
cut control is completed before the drum 69 makes a turn, there is no 
possibility that the motors generate heat and the brake shoe 117 are worn. 
The time till T&gt;3 which comes to be satisfied can be shortened by somewhat 
performing the direct current braking before counting the time T. 
Effects not mentioned above and still another embodiment will be presented 
below. 
(1) In each process above stated, the drum 69 necessarily starts in the 
direction of the forward rotation of the washer motor 106. This direction 
is changed to the direction opposite to the direction of closing the lid 
98, so that the lid 98 automatically closes because of the reaction in 
starting the drum 69, even if the lid 98 is left half-opened. 
(2) The top end of the tube 18 is set at the level almost the same as the 
virtual circumferential plane 2a of the outer tub 2, and the mounting 
bosses 20 of the packing 24 are provided out of this level, whereby the 
protrusion of the tube 18 can be lowered as much as possible, and the 
laundry can be easily taken in and out. 
(3) The claw 25 with which the safety cover 29 interlocks from the lower 
part is provided in the gasket 26 for pressing the top end 24b of the 
rubber packing 24. Thus, the force of the interlock acts for the 
horizontal wall 26b of the gasket 26 like a lever with the screws 27 as 
its fulcrum. The end portion of the horizontal wall 26b is pressed 
downward, whereby the sealing capability against water is enhanced between 
the rubber packing 24 and the rim 22a of the opening A 22. 
(4) Since the filter unit 87 is placed close to the opening C 92 of the 
drum 69, the filter unit 87 can be easily attached and detached. 
(5) The wall 37a of the air duct A 37, which covers the cylinder 36 is 
positioned close to the cylinder 36, and then the rear drum bearing 38 is 
fixed to the wall 37a. In this way, the drum shaft 79 can be shortened, 
and moreover, air pressure is increased because of the sectional area of 
the wall 37a is reduced. 
(6) Each of the bores 74 is widened along the outward radial direction of 
the drum 69 as shown in FIG. 18, whereby external heated air is 
increasingly introduced into the drum 69, and the drying efficiency is 
enhanced. In addition to that, the laundry is dehumidified from the outer 
portion, and thus, the laundry easily comes off the drum 69 when it is 
completely dehumidified. 
Since additional parts are employed as shown in FIG. 19, it is not 
necessary for the drum 69 to be subjected to any special processing, and 
the manufacturing cost can be reduced. 
(7) Concave portions 167 and convex portions 168 are alternately placed 
checkerwise on the inner surface of the drum 69 as shown in FIG. 26, 
whereby the laundry does not easily cling to the inner surface of the drum 
69. On washing, the laundry rubs against the drum along the 
circumferential and axial directions, and thus the washing capability can 
be enhanced. 
(8) A rubber bulging member 169 having hair-like protuberances on its 
surface as shown in FIG. 27 is provided on the inner surface of the drum 
69, so that the laundry easily comes off the drum 69 because of the 
elastic force of the rubber member. 
(9) A rubber band 171 having projections 170 loosely fitting into the bores 
74 as shown in FIGS. 28 and 29 is wound around the outer peripheral 
surface of the drum 69. In the hydroextracting operation, the projections 
170 is pressed out by the centrifugal force and the rubber band 171 is 
stretched, as shown in FIG. 29(a). This never reduces the hydroextracting 
efficiency. After the hydroextracting operation, the projections 170 
protrudes into the drum 69 and push the laundry off the drum 69. 
Apertures 172 may be formed in the projections 170 in the rubber band 171, 
as shown in FIG. 30. Thus, the projections 170 never prevent water from 
coming out of the drum 69. 
(10) The angles .theta..sub.1, .theta..sub.2 of the horizontal ribs 75 
provided in the baffle 73 are determined as mentioned above, whereby the 
laundry can be assuredly carried up in the drum 69 even when the drum 69 
rotates at low speed. 
(11) The outer tub 2 is supported by the upper supporting members 5 and the 
lower supporting members 15, whereby in the hydroextracting operation, the 
outer tub 2 decreases in the vertical and lateral amplitude, especially 
the amplitude at starting time, and thus, the vibration of the machine 
body can be suppressed. 
Generally, the vibration suppressing force F for a vibration proofing 
member is represented as F=mx+cx+kx+.mu.p . . . (1), where m is mass, c is 
attenuation coefficient, k is spring constant, .mu. is friction 
coefficient, x is acceleration, x is speed, x is displacement and p is 
vertical force against the friction plane. 
With the upper supporting member 5 and the lower supporting member 15 
according to the present invention, the vibration is attenuated by the 
expansion and contraction force of the spring A 11 and the spring B 16, 
and the mutual frictional force between the supporting rod 9 and the 
aperture 7a, and between the spring B 16 and the elastic cylinder. The 
above equation (1) comes to be F=kx+.mu.p . . . (2) for both the upper and 
lower supporting members 5 and 15. When the vibration is suppressed, the 
.mu. has a significant influence; particularly, since static friction 
coefficient is larger than kinetic friction coefficient, the vibration at 
the starting time is very effectively suppressed. The elastic cylinder 17 
of the lower supporting member 15 has restoring force against deformation 
and is considerably helpful for suppressing the lateral vibration. 
FIGS. 31 and 32 present experimental proofs of the aforementioned matters. 
FIG. 32 shows the relations between vibration characteristics and time, and 
FIG. 31 shows the vibration characteristics for different loads. In any 
cases, the amplitude can be considerably suppressed compared to a prior 
art embodiment. 
As the prior art example, a spring unity is used for an upper supporting 
member, and a shock absorber is used for a lower supporting member. 
According to such a prior art embodiment, the upper vibration suppressing 
force F.sub.1 is given by the extension and contraction of a spring. From 
the above equation (1), F.sub.1 =kx . . . (3) is obtained. The lower 
vibration suppressing force F.sub.2 given by the shock absorber is in 
accordance with the change in speed, and F.sub.2 =cx . . . (4) is 
obtained. 
With regard to the equation (3), since merely the expansion and contraction 
of the spring acts the suppressing force, an attenuating time of the 
vibration is long. With regard to the equation (4), the suppressing force 
F.sub.2 is extremely small at the starting time when the speed is almost 
zero, and experimental data proves the assumption is correct. 
With regard to the vibration attenuating property of the spring, good 
following property of the spring causes resonance phenomena soon after the 
starting, as shown by point A in FIG. 32. In this embodiment, since the 
friction force also acts, the resonance phenomena is not so significant, 
and the vibration is easily attentuated, and thus, it takes short time to 
start the normal rotation (t1&lt;t2). 
FIG. 33 shows further another embodiment where the upper supporting members 
5 has an elastic cylinder 174 placed surrounding a spring C 173 similar to 
the lower supporting member 15. 
(12) FIG. 45 shows another example of the abnormal foam sensing circuit 
employing the electrodes 44, 44. 
One of the electrodes 44, 44 is connected to a terminal PA of the 
microcomputer 125 through resistances R.sub.1, R.sub.2 and a transistor A 
175 (2SA1317-type), and the other electrode 44 is connected to a terminal 
PB of the microcomputer 125 through a resistance R.sub.3 and a transistor 
B 176 (2SC3331-type). The resistances R.sub.2, R.sub.4 are resistances for 
limiting current, and the resistance RT is a resistance for ensuring the 
turning-ON and -OFF of the transistors. 
During the washing process, the microcomputer 125 has its terminal PA 
grounded. When the foam generated makes the electrodes 44, 44 conductive, 
the transistor B 176 turns on, and the terminal PB is grounded. In this 
way, the microcomputer 125 recognizes the foam generated. During processes 
other than the washing process, the terminal PA is left disconnected not 
to turn the transistor A 175 on. In this way, false sensing due to the 
water splashing on the electrodes 44, 44 is avoided, and the corrosion of 
the electrodes 44, 44 can be prevented because no electric current flows. 
FIG. 66 shows an equivalent circuit for determining the resistances R.sub.1 
to R.sub.4 and RT. 
In FIG. 66, the potential at the point A is given by the following formula: 
##EQU1## 
where x is resistance of the foam. 
In order to turn the transistor B 176 on, the potential at the point A must 
be more than about 0.7 V. Allowing for that the resistance of the foam is 
about 50 K.OMEGA. and assuming that R.sub.1 =R.sub.3 =5.6 K.OMEGA., 
R.sub.T =12 K.OMEGA. and Vcc=5 V, it is found that the potential at the 
point A is about 0.82 V from the formula (a), and the foam can be sensed 
by the electrodes 44, 44. 
The resistance of vapor in the atmospheric air is more than several 
M.OMEGA.. Assuming x=1M.OMEGA., it is found from the formula (a) that the 
potential at the point A is about 0.059 V, and the transistor B 176 never 
turn on. Thus, the conduction of the electrodes 44, 44 due to the vapor in 
the air is never sensed. 
(13) Another embodiment of the foam sensing means will be explained with 
reference to FIGS. 46 and 47. 
A partition plate 177 is integrally formed on the bottom surface of a lid 
178 which covers the upper face of the overflow pipe 43, hanging down from 
the bottom surface of the lid 178. The partition plate 177 separates the 
inner room of the overflow pipe 43 into two cells 179, 180 which 
communicate with each other only in the lower part. The overflow outlet 42 
is provided on the upper part of the cell 179 of the two cells 179, 180. A 
pair of rod-shaped electrodes 181, 182 as the foam sensing means is 
suspended from the lid 178 in the cell 180 of the two cells 179, 180. 
These electrodes 181, 182 become conductive similar to the electrodes 44, 
44 when the excessive foam is generated and sends a signal to the 
microcomputer 125. 
Elastic insulating members 183, 184 are attached to protect the mounting 
portion of the electrodes 181, 182 and to prevent the electrodes 181, 182 
from bending at respective roots. A joint pipe 185 as a part of the water 
supply means is integrally formed on the lid 178. A water supply branch 
pipe 187 as a part of the water supply means, which is branching away from 
the inlet hose A 65, is connected to one end 186 projecting over the upper 
face of the lid 178. The other end 188 projects between the electrodes 
181, 182 below the bottom face of the lid 178. Ports 189, 190 are provided 
on both sides of the other end 188, directed to the root portions of the 
electrodes 181, 182. 
A separating plate 191 is integrally provided, hanging down from the other 
end 188 of the joint pipe 185, and its lower end reaches a position under 
the electrodes 181, 182. The separating plate 191 is wide enough to 
conceal the electrodes 181, 182 from each other, but is narrower than the 
partition wall 177. An outlet 192 is provided at the end of the overflow 
hose 56, and is projected upwardly from the overflow pipe 43. A ventilator 
193 is provided in a position lower than the upper end of the outlet 192 
to communicate the outer tub 2 and the overflow pipe 43. The ventilator 
193 is smaller in the area of its opening than the outlet 192. 
Thus, while water is supplied to the outer tub 2, water is also introduced 
into the cell 180 of the overflow pipe 43 from the water supply branch 
pipe 187. The water supplied into the cell 180 is poured from the ports 
189, 190 onto the electrodes 181, 182 to clean them from their roots. 
(14) Different embodiments of the abnormal foam managing program (FIG. 36) 
will be described with reference to FIGS. 48 to 53. 
In FIG. 48, when the abnormal foaming is sensed, the washing operation is 
temporarily stopped (S-200), and water supply to the tub begins (S-201). 
The water supplying operation is carried out for ten seconds. Five seconds 
after the beginning of the water supply, water is also discharged (S-202) 
to (S-205). The discharging operation is completed when the water level in 
the tub reaches the Low level (S-206). Then, after water is supplied to 
the set level again (S-207) (S-208), the washing operation is started 
again (S-209). 
In this way, in the defoaming operation, water is resupplied and thereafter 
the water in the tub is discharged so that the washing water which has 
been defoamed by supplying water is discharged. Thus, there is no 
possibility the foam flows reversely from the overflow hose 56 to the 
overflow pipe 43. 
In FIG. 49, when the abnormal foaming is sensed, the washing operation is 
temporarily stopped (S-210), and a counter starts counting a defoaming 
time T (S-211). At the same time, the water supply valve A 64a is 
repeatedly driven in the cycle where it turns ON for 2 seconds and OFF for 
2 seconds to intermittently supply water to the tub (S-212) to (S-217). 
After the defoaming time T, 30 seconds, has elapsed, the water in the tub 
is discharged while water is being supplied (S-218). When a discharging 
time T, 1 minutes, has elapsed, water supply and drainage are completed 
(S-219), and the washing operation starts again (S-220). 
In FIG. 50, when the abnormal foaming is sensed, the drum is rotated 
through the 1/3 pulse cut control in the washing operation (S-221), and 
water supply to the tub starts (S-222). The water supplying operation 
continues for 15 seconds. Five seconds after the beginning of the water 
supply, the water in the tub 2 is also discharged for five seconds (S-223) 
to (S-225). 15 seconds after, the water supply is completed (S-226), and 
the washing operation is started again (S-227). 
In FIG. 51, when the abnormal foaming is sensed, the fan motor 60 is driven 
to introduce air into the tub (S-230). At the same time, the drum is 
rotated through the 1/3 pulse cut control in the washing operation 
(S-231), and then water supply is started (S-232). The water supplying 
operation is carried out for 15 seconds. 5 seconds after the beginning of 
the water supply, the water in the tub 2 is also discharged for five 
seconds (S-233) to (S-235). When 15 seconds has elapsed, the water supply 
is completed (S-236), and the fan motor 60 is turned off (S-237), and the 
washing operation is started again (S-238). 
1/2 pulse cut control is a braking operation as previously mentioned, but 
it does not stop the drum 69 completely; the drum 69 very slowly rotates 
under this control (at 1/10 speed compared with the speed in successively 
turning the motor on). The control at the steps S-221 and S231 is not 
limited to the 1/3 pulse cut control, but the 1/2 pulse cut control may be 
employed. 
In FIG. 52, the turn-on of the heater B 68 in the washing process is 
delayed by 1 minute after the water supply is completed (S-240) to 
(S-242). If the abnormal foaming is sensed during this 1 minute (S-243), 
the defoaming program is carried out (S-244) (S-245). After the 1 minute 
has elapsed, the heater B 68 is turned on to heat the washing water 
(S-246) (S-247), and the washing operation is continued (S-248). 
In FIG. 53, when the abnormal foaming is sensed in the washing operation 
and the defoaming control is carried out (S-250) (S-251), the RAM 127 
stores it (S-251). After the operation is completed, the buzzing circuit 
146 or the LED drive circuit 147 receives instructions to give an alarm 
sound or light up and out all the LEDs in the operating unit 21a, so as to 
warn the user not to overuse washing agent (S-253). Ten minutes after the 
completion of the operation, the power source is automatically shut off, 
and the warning operation of the LEDs is also completed (S-254). 
In the above embodiment, similar to the embodiment described in conjunction 
with FIG. 36, a period of time for the water supply and drainage may be 
varied in accordance with the degree of the foaming. 
(15) In FIG. 54, after the water supply in the washing process is completed 
(S-260), for initial two minutes of the drum reversal operation (for 
example, 12 minutes), the drum 69 is rotated reversely in the cycle of ON 
for 2 seconds--OFF for 15 seconds (S-261); and for the remaining period of 
time (10 minutes), the normal operation is carried out (S-262). Namely, 
the reversal cycle where a relatively long period of time is allotted for 
a pause is employed at the beginning of the washing. In this way, the 
foaming is suppressed while surface activating effect of the washing agent 
separates soil from the laundry into the washing water. The washing water, 
when made turbid by the soil, comes not to easily produce foam, and 
therefore, after the soil has been separated, the drum 69 is rotated in 
the usual reversal cycle. On the reversal operation at the step S-261, the 
rotating speed of the drum may be reduced through the pulse cut control 
instead of protracting the pause. 
As shown in FIG. 55, the period of time for the drum reversal operation 
(for example, 12 minutes) is divided into three terms; first term (4 
minutes), middle term (4 minutes) and last term (4 minutes). After water 
supply is completed (S-270), the drum 69 may be rotated in the cycle of ON 
for 2 seconds and OFF for 15 seconds at the first term (S-271), ON for 10 
seconds and OFF for 2 seconds at the middle term (S-272) and ON for 15 
seconds and OFF for 1 second at the last term (S-273). 
As shown in FIG. 56, after the water supply is completed (S-280), the drum 
reversal cycle is set ON for 1 second--OFF for 15 seconds at the beginning 
of a period of time T for the drum reversal operation (S-281). Then, every 
1 minute elapsed, the ON-time in the reversal cycle may be increased by 1 
second while the OFF-time is decreased by 1 second (S-282) to (S-286). 
In an embodiment shown in FIGS. 54 to 56, the ON-time (operating time) in 
the drum reversal cycle at the beginning of the washing is set at 1 second 
or 2 seconds. This ON-time is desirably a period of time under the time 
necessary for a turn of the drum 69; while the drum 69 is making a turn, 
the laundry is carried up and dropped, and this enhances foaming. For 
example, if the rotating number of the drum 69 is 60 r.p.m, a turn of the 
drum 69 takes 1 second, and hence the above-mentioned ON-time is desirably 
under 1 second. According to the experiment, the optimum condition of the 
reversal cycle at the beginning of the washing is 1/4 turn of the drum for 
0.25 second. 
(16) As shown in FIG. 57, a washing-after-soaking process may be carried 
out before the washing process by giving instructions with the keys in 
advance. 
In the washing-after-soaking, first water is supplied at the highest water 
level ("High" water level) in the tub 2 (S-290), and then the laundry is 
left in the tub 2 for one minute (S-291). The laundry absorbs the washing 
water for that period, and the water level is lowered. After water is 
supplied to the highest water level again (S-292) (S-293), counting 1 hour 
begins (S-294). For that period of time, the drum 69 is rotated for five 
seconds every five minutes at low speed (S-295). For the five-minute pause 
the surface activating effect of the washing agent separates soil from the 
laundry, and the five-second rotating operation diffuses the soil into the 
washing water. 
One hour after, the water level is lowered to the set level for the washing 
process (S-296) (S-297), and then the washing process is carried out 
(S-298). 
While the laundry is left in the tub 2 at the step S-291, 291, the drum 69 
may be rotated for a short time to force the laundry to absorb the washing 
water. 
(17) As shown in FIG. 5, a tail portion 194 of the inlet hose A 65 is 
horizontally held and connected to the opening 66. The tail portion 194 is 
shaped like bellows. The horizontal vibration of the outer tub 2 can be 
absorbed by the expansion and contraction of the bellows. 
FIG. 58 shows an example where a spring 195 is inserted into the tail 
portion 194. With this hose A 65, vibration absorbing effect can be 
further enhanced. 
(18) As shown in FIG. 59, a concave portion 196 is integrally formed along 
one edge portion of the lid 98 to receive the pull 99, and the concave 
portion 196 engages with the rib 97 at the opening C 92 when the lid 98 is 
left opened. Thus, there is no need of providing any member to engage with 
the rib 97. Putting his or her hand in the concave portion 196 to open the 
lid 98, the user feels the shock of the engagement, and thus it is easy 
for the user to recognize that the lid 98 has opened completely. 
Additionally, the concave portion 196 is helpful for preventing the 
deformation of the lid 98. 
(19) As shown in FIG. 59, a weight 197 is placed at an end corresponding to 
the openwise direction of the lid 98. The weight 197 always urges the lid 
98 in the openwise direction, and thus the lid 98 is easily opened. 
(20) As shown in FIG. 60, a distance W between the slide groove 93 and 94 
is gradually made large along the openwise direction of the lid 98 (W1 
W2). As a result, as the lid 98 approaches its opening position, the slide 
resistance of the lid 98 is increased. If the lid 98 is opened with 
considerable force, the force is relieved. Thus, the possibility that the 
lid 98 is accidentally damaged or it goes bump with the rib 97 can be 
reduced. 
As shown in FIGS. 61 and 62, the depth P1 of the slide groove 93 is 
gradually made small along the openwise direction (shown by the arrow in 
these figures), while the thickness P2 of the slide groove 94 is gradually 
made large along the openwise direction of the lid 98. In this way, too, 
the slide resistance of the lid 98 can be increased as the lid 98 
approaches its opening position. 
(21) As shown in FIGS. 63 and 64, horizontal ribs 198 similar to the 
horizontal rib 75 are integrally formed on the inner surface of the lid 
98. This enhances the cleaning efficiency, and moreover, prevents the 
laundry from clinging to the inner surface of the lid 98. In this way, the 
trouble that a handkerchief and stuff like clinging to the inner surface 
of the lid 98 gets jammed between the lid 98 and the drum 69 when the lid 
98 is opened can be avoided. 
(22) As shown in FIGS. 64 and 65, opposite ends of the mounting plate 4 are 
extended and bent up to form supporting portions 199, 200 protruding in 
the horizontal direction over the horizontal supporting face 3. The lower 
supporting members 15 are fixed to the supporting portions 199, 200. In 
this way, the lower supporting members 15 extends its entire stretch. As a 
result, the spring B 16 increases in the amount of expansion and 
contraction, and the vibration can be effectively attenuated. 
Moreover, a supporting rib 201 is integrally formed on the side of the 
outer tub 2 to engage with the supporting portions 199, 200, so as to 
prevent the deformation of the supporting portions 199, 200.