U.S. patent application number 10/751466 was filed with the patent office on 2005-01-27 for drum washing machine.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Kim, Hyun Suk, Kim, Hyung-Gyoon, Oak, Seong Min, Park, Jae-Ryong, Park, Seon-Woo, Pyo, Sang-Yeon, Yang, Byoung Yull, Yang, Hye Soon.
Application Number | 20050015892 10/751466 |
Document ID | / |
Family ID | 33487939 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050015892 |
Kind Code |
A1 |
Park, Jae-Ryong ; et
al. |
January 27, 2005 |
Drum washing machine
Abstract
A drum washing machine that uses less wash water, reduces an
amount of electricity required to heat the wash water, and reduces
washing time. The drum washing machine includes a water tub to
contain water therein; a rotary drum provided in the water tub so
that a rotating axis of the rotary drum is inclined relative to a
horizontal axis at a predetermined first angle of inclination to
allow an inlet opening of the rotary drum to be directed upward and
forward, with a drain hole provided on the rotary drum at a
position adjacent to the inlet opening, and an internal surface of
the rotary drum being inclined relative to the rotating axis of the
rotary drum at a predetermined second angle of inclination so as to
guide the water to the drain hole, prior to discharging the water
from the rotary drum to an outside of the rotary drum through the
drain hole; a drive unit to drive the rotary drum; and a water
circulation unit to feed the water from the water tub into the
rotary drum.
Inventors: |
Park, Jae-Ryong;
(Suwon-City, KR) ; Kim, Hyung-Gyoon; (Suwon-City,
KR) ; Pyo, Sang-Yeon; (Suwon-City, KR) ; Park,
Seon-Woo; (Suwon-City, KR) ; Yang, Hye Soon;
(Yongin-City, KR) ; Oak, Seong Min; (Masan-City,
KR) ; Yang, Byoung Yull; (Ansan-City, KR) ;
Kim, Hyun Suk; (Seoul, KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700
1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
33487939 |
Appl. No.: |
10/751466 |
Filed: |
January 6, 2004 |
Current U.S.
Class: |
8/159 ; 68/140;
68/184; 68/207; 68/208; 68/24; 68/58 |
Current CPC
Class: |
D06F 39/083 20130101;
D06F 23/06 20130101; D06F 37/04 20130101 |
Class at
Publication: |
008/159 ;
068/024; 068/058; 068/140; 068/184; 068/207; 068/208 |
International
Class: |
D06F 039/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2003 |
KR |
2003-50656 |
Claims
What is claimed is:
1. A drum washing machine, comprising: a water tub to contain water
therein; a rotary drum included in the water tub and comprising: a
rotating axis of the rotary drum is inclined relative to a
horizontal axis at a predetermined first angle of inclination
allowing an inlet opening of the rotary drum to be directed upward
and forward, a drain hole provided on the rotary drum at a position
adjacent to the inlet opening, and an internal surface of the
rotary drum being inclined relative to the rotating axis of the
rotary drum at a predetermined second angle of inclination so as to
guide the water to the drain hole, prior to discharging the water
from the rotary drum to an outside of the rotary drum through the
drain hole; a drive unit to drive the rotary drum; and a water
circulation unit to feed the water from the water tub into the
rotary drum.
2. The drum washing machine of claim 1, further comprising a heater
provided in a lower portion of the water tub which heats the
water.
3. The drum washing machine of claim 2, further comprising a drain
unit having a drain pipe connected to the lower portion of the
water tub and a drain pump mounted to an intermediate portion of
the drain pipe.
4. The drum washing machine of claim 3, wherein the water
circulation unit comprising: a control valve mounted to the drain
pipe of the drain unit at a position around an outlet of the drain
pump to control a flow direction of the water flowing from the
drain pump; a water circulation pipe extending from the control
valve to the inlet opening of the rotary drum; and a spray nozzle
mounted to an outlet of the water circulation pipe to spray the
water into the rotary drum.
5. The drum washing machine of claim 1, further comprising a drain
unit having a drain pipe connected to a lower portion of the water
tub and a drain pump mounted to an intermediate portion of the
drain pipe.
6. The drum washing machine of claim 1, wherein the water
circulation unit comprising: a control valve mounted to the drain
pipe of the drain unit at a position around an outlet of the drain
pump to control a flow direction of the water flowing from the
drain pump; a water circulation pipe extending from the control
valve to the inlet opening of the rotary drum; and a spray nozzle
mounted to an outlet of the water circulation pipe to spray the
water into the rotary drum.
7. The drum washing machine of claim 1, wherein the rotary drum
comprising: a rear part which is closed and coupled to a rotating
shaft at a center of the rear part; a front part spaced apart from
the rear part, with the inlet opening provided at a central portion
of the front part, and the drain hole provided on an edge of the
inlet opening of the front part; and a sidewall part which is
closed and extends between the rear part and the front part wherein
an inner diameter of the sidewall part increases along a direction
from the rear part to the front part to allow an internal surface
of the sidewall part to be inclined.
8. The drum washing machine of claim 7, wherein the drain hole
comprising a plurality of rows of drain holes provided around an
edge of the front part of the rotary drum.
9. The drum washing machine of claim 1, wherein the rotary drum
comprising: a rear part which is closed and coupled to a rotating
shaft at a center of the rear part; a front part spaced apart from
the rear part, with the inlet opening provided at a central portion
of the front part; and a sidewall part which is closed and extends
between the rear part and the front part wherein an inner diameter
of the sidewall part increases along a direction from the rear part
to the front part to allow an internal surface of the sidewall part
to be inclined, the sidewall part having the drain hole which is
provided on an edge of the sidewall part adjacent to the front
part.
10. The drum washing machine of claim 1, wherein the rotary drum
comprising: a rear part, with a rotating shaft coupled to a center
of the rear part; a front part spaced apart from the rear part,
with the inlet opening provided at a central portion of the front
part; and a sidewall part extending between the rear part and the
front part wherein an inner diameter of the sidewall part increases
along a direction from the rear part to the front part to allow an
internal surface of the sidewall part to be inclined, the sidewall
part being connected to the front part along a rounded junction
surface, with the drain hole formed on the rounded junction
surface.
11. A drum washing machine, comprising: a water tub to contain
water therein; and a rotary drum installed in the water tub by use
of a rotating shaft and comprising: an internal surface of the
rotary drum being inclined relative to a rotating axis of the
rotary drum so that an inner diameter of the rotary drum increases
along a direction from a rear part coupled to the rotating shaft to
a front part having an inlet opening, the rotary drum being closed
around a sidewall part thereof, and a drain hole being provided on
the rotary drum at a position adjacent to the inlet opening.
12. A drum washing machine, comprising: a water tub to contain
water therein; a rotary drum included in the water tub to be
inclined so that a front part of the rotary drum having an inlet
opening is positioned to be higher than a rear part of the rotary
drum coupled to a rotating shaft and comprising: an internal
surface of the rotary drum being inclined so that an inner diameter
of the rotary drum increases along a direction from the rear part
to the front part, and a drain hole provided on the rotary drum at
a position adjacent to the inlet opening of the front part; a drive
unit to drive the rotary drum; and a water circulation unit to feed
the water from the water tub into the rotary drum.
13. The drum washing machine of claim 9, wherein the drain hole
comprising a plurality of drain holes provided on the edge of the
sidewall part adjacent to the front part of the rotary drum.
14. The drum washing machine of claim 10, wherein the drain hole
comprising a plurality of drain holes provided on the edge of the
sidewall part adjacent to the front part of the rotary drum.
15. The drum washing machine of claim 11, wherein the drain hole
comprising a plurality of drain holes provided on the edge of the
sidewall part adjacent to the front part of the rotary drum.
16. The drum washing machine of claim 12, wherein the drain hole
comprising a plurality of drain holes provided on the edge of the
sidewall part adjacent to the front part of the rotary drum.
17. The drum washing machine of claim 1, further comprising: a
detergent supplying unit; and a water supplying unit installed in a
cabinet above the water to respectively feed each of a detergent
and water into the water tub.
18. The drum washing machine of claim 17, wherein the detergent
supply unit is placed at a front part of the cabinet to allow the
user to feed the detergent into the water tub.
19. The drum washing machine of claim 17, wherein the water supply
unit comprising: a first water feed pipe which extends from an
external water supply pipe to the detergent supply unit; a second
water feed pipe which extends from the detergent supply unit to the
water tub; and a control valve which is mounted to an intermediate
portion of the first water feed pipe to control a flow of the water
to be fed into the water tub.
20. The drum washing machine of claim 2, wherein the heater is
installed in a heater holding part in which a predetermined amount
of water is collected to a level to allow the heater to be
submerged into the water.
21. The drum washing machine of claim 21, wherein the heater
holding part has a pan-shaped appearance.
22. The drum washing machine of claim 5, wherein the drain pipe
comprising: a first drain pipe connected to a drain port provided
at the lower portion of the water tub; and a second drain pipe
which extends from an outlet of the drain pump and allows water to
be drained to an outside of a cabinet.
23. A method of washing laundry in a drum washing machine, the
method comprising: feeding water into a water tub; stopping the
water supplied into the water tub after a predetermined amount of
water is fed into the water tub; holding the water in a heater
holding part provided at a lower portion of a sidewall part of the
water tub prior to feeding the water into a rotary drum; feeding
the water into the rotary drum; overflowing water from the rotary
drum into the water tub when a level of the water in the rotary
drum exceeds a height of a drain hole in a lowermost position on
the rotary drum; circulating the water from the water tub to the
rotary drum continuously so that the water tub contains a small
amount of water therein; rinsing the laundry; and spin-drying the
laundry.
24. The method of claim 23, wherein the feeding water into the
water tub comprising supplying water to a detergent supply unit
prior to the water reaching the water tub due to coupling of the
detergent supply unit and a water supply unit.
25. The method of claim 23, wherein the holding the water in the
heater holding part comprising heating the water to a predetermined
temperature using a heater.
26. The method of claim 23, wherein the feeding the water into the
rotary drum comprising spraying the laundry contained in the rotary
drum with water using a spray nozzle while simultaneously rotating
the rotary drum at a low speed.
27. The method of claim 23, wherein the rinsing of the laundry
comprising: spin-drying the laundry wherein the rotary drum is
rotated at a high speed and the water is spin-dried out of the
laundry in the rotary drum to move radially outward to an internal
surface of a sidewall of the rotary drum due to a centrifugal force
and is secondarily guided to a plurality of drain holes provided on
a front part of a rotary drum and discharged to the outside of the
rotary drum through the plurality of drain holes and drained to an
outside of a cabinet; and supplying new water into the water tub to
rinse the laundry.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Application
No. 2003-50656, filed on Jul. 23, 2003, in the Korean Intellectual
Property Office, the disclosure of which is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a drum washing machine and,
more particularly, to a drum washing machine that uses less water,
reduces an amount of electricity required to heat the water, and
reduces washing time.
[0004] 2. Description of the Related Art
[0005] In a conventional drum washing machine, a cylindrical rotary
drum which is set in a drum-type water tub inside a cabinet, is
rotated to repeatedly move upward laundry, seated on an internal
surface of the rotary drum, along with water, thus causing the
laundry and water to be dropped from a top to a bottom inside the
rotary drum due to gravity, and thereby washing the laundry. An
example of a conventional drum washing machine is disclosed in
Japanese Patent Laid-open Publication No. 2001-149685. This
conventional drum washing machine has a function of heating water
to enhance the washing effect.
[0006] The conventional drum washing machine includes a water tub,
a rotary drum, and a heater. The water tub contains water therein,
while the rotary drum having a plurality of perforations around a
sidewall thereof is rotatably set in the tub. The heater is
installed at a predetermined position under the water tub so as to
heat the water to a predetermined temperature. When the drum
washing machine is operating and both water and detergent are fed
into the water tub, the rotary drum is rotated in the tub at a low
speed. During the washing operation of the washing machine, the
heater heats the water to a predetermined temperature, thereby
enhancing the washing effect of the washing machine.
[0007] However, the conventional drum washing machine may have
several problems. That is, it is necessary to feed water into the
washing machine to a level at which the laundry inside the rotary
drum is sunk in the water which is also contained in a gap between
the perforated rotary drum and the water tub. Therefore, the
conventional drum washing machine must consume an excessive amount
of water. Since the conventional drum washing machines are designed
so that the water is fed into the water tub, and flows into the
rotary drum through the perforations of the rotary drum until the
laundry in the rotary drum is sunk in the water, a large amount of
water must be fed into the water tub. Consumption of the water
during the operation of the washing machine while in washing and
rinsing operations is thus excessively increased, leading to an
increase in cost.
[0008] Since the excessive amount of water is consumed during an
operation of the conventional drum washing machine, the washing
machine requires long periods of time for feeding or draining the
water into or from the water tub. In addition, the time for which
the conventional drum washing machine washes the laundry is further
increased since the water must be heated to a predetermined
temperature by the heater, before the rotary drum starts to be
rotated to wash the laundry with the heated water. Furthermore,
since the large amount of water must be heated to the predetermined
temperature by the heater, the conventional drum washing machine
excessively uses electricity to heat the water.
[0009] Another disadvantage in the conventional drum washing
machine is that it is very difficult to produce the rotary drum,
resulting in a complex production process of the washing machines,
since the perforations must be formed around the sidewall of the
rotary drum to allow the water to flow between the inside of the
water tub and the rotary drum, and to allow the rotary drum to
spin-dry the laundry during a spin-drying operation.
SUMMARY OF THE INVENTION
[0010] Accordingly, it is an aspect of the present invention to
provide a drum washing machine, which uses less water, and reduces
an amount of electricity required to heat the water, and reduces
washing time, without reducing the washing effect of the drum
washing machine.
[0011] It is another aspect of the present invention to provide a
drum washing machine, which has a rotary drum designed to be easily
produced.
[0012] Additional aspects and/or advantages of the invention will
be set forth in part in the description which follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
[0013] The foregoing and/or other aspects of the present invention
are achieved by providing a drum washing machine comprising a water
tub to contain water therein, and a rotary drum provided in the
water tub wherein a rotating axis of the rotary drum is inclined
relative to a horizontal axis at a predetermined first angle of
inclination allowing an inlet opening of the rotary drum to be
directed upward and forward, with a drain hole provided on the
rotary drum at a position adjacent to the inlet opening, and an
internal surface of the rotary drum being inclined relative to the
rotating axis of the rotary drum at a predetermined second angle of
inclination so as to guide the water to the drain hole, prior to
discharging the water from the rotary drum to an outside of the
rotary drum through the drain hole, a drive unit to drive the
rotary drum, and a water circulation unit to feed the water from
the water tub into the rotary drum.
[0014] The drum washing machine may further comprise a heater
provided in a lower portion of the water tub so as to heat the
water.
[0015] The drum washing machine may further comprise a drain unit
having a drain pipe connected to the lower portion of the water tub
and a drain pump mounted to an intermediate portion of the drain
pipe.
[0016] The water circulation unit may comprise a control valve
mounted to the drain pipe of the drain unit at a position around an
outlet of the drain pump to control a flow direction of the water
flowing from the drain pump, a water circulation pipe extending
from the control valve to the inlet opening of the rotary drum, and
a spray nozzle mounted to an outlet of the water circulation pipe
to spray the water into the rotary drum.
[0017] The rotary drum may comprise a rear part which is closed and
coupled to a rotating shaft at a center of the rear part, a front
part spaced apart from the rear part, with the inlet opening
provided at a central portion of the front part, and the drain hole
provided on an edge of the inlet opening of the front part, and a
sidewall part which is closed and extends between the rear part and
the front part wherein an inner diameter of the sidewall part
increases along a direction from the rear part to the front part to
allow an internal surface of the sidewall part to be inclined.
[0018] The drain hole may comprise a plurality of rows of drain
holes which are provided around an edge of the front part of the
rotary drum.
[0019] It is another aspect of the present invention to provide a
drum washing machine wherein the rear part and the sidewall part of
the rotary drum may be closed, and the drain hole may be provided
on an edge of the sidewall part adjacent to the front part.
[0020] It is another aspect of the present invention to provide a
drum washing machine wherein the sidewall part of the rotary drum
may be connected to the front part along a junction which is
rounded to provide a rounded junction surface, with the drain hole
formed on the rounded junction surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the
following description of the embodiments taken in conjunction with
the accompanying drawings of which:
[0022] FIG. 1 is a sectional view of a drum washing machine
according to an embodiment of the present invention, when the
washing machine is in a washing operation;
[0023] FIG. 2 is a sectional view of the drum washing machine of
FIG. 1, when the washing machine is in a spin-drying operation;
[0024] FIG. 3 is a sectional view taken along a line of III-III' of
FIG. 1;
[0025] FIG. 4 is a perspective view of a rotary drum included in
the drum washing machine of FIG. 1;
[0026] FIG. 5 is a sectional view of the rotary drum of FIG. 4;
and
[0027] FIGS. 6 and 7 are sectional views of a rotary drum, with
drain holes provided on the rotary drum according to a first
modification and a second modification of the embodiment of FIG. 1,
respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Reference will now be made in detail to the embodiments of
the present invention, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to
like elements throughout. The embodiments are described below to
explain the present invention by referring to the figures.
[0029] As shown in FIG. 1, a drum washing machine according to the
present invention includes a cabinet 10, a drum-type water tub 11,
and a rotary drum 20. The drum-type water tub 11 is installed in
the cabinet 10, and contains water therein. The rotary drum 20 is
rotatably set in the water tub 11.
[0030] In the cabinet 10, the water tub 11 is installed to be
inclined relative to a horizontal axis of the cabinet 10 at a
predetermined first angle a of inclination, such that a front part
11a of the water tub 11 having an inlet opening 11b is placed at a
position higher than a rear part 11c of the water tub 11. In the
same manner as the water tub 11, the rotary drum 20 is installed in
the water tub 11 such that a front part 22 of the rotary drum 20
having an inlet opening 23 is placed at a position higher than a
rear part 21 of the rotary drum 20. That is, a rotating axis A of
the rotary drum 20 is inclined relative to the horizontal axis of
the cabinet 10 at the first angle .alpha. of inclination to allow
the front part 22 having the inlet opening 23 to be placed at the
position higher than the rear part 21. A rotating shaft 12, which
is securely mounted to a center of the rear part 21 of the rotary
drum 20, is rotatably held in a center of the rear part 11 c of the
water tub 11, thus allowing the rotary drum 20 to be rotated
relative to the water tub 11. The water tub 11 is suspended in the
cabinet 10 by a plurality of shock absorbing suspension units (not
shown) while being apart from an internal surface of the cabinet
10.
[0031] A motor 13 that is a drive unit to rotate the rotating shaft
12 of the rotary drum 20 is installed at a position outside the
rear part 11 c of the water tub 11. The motor 13 includes a stator
13a which is mounted to the rear part 11c of the water tub 11, a
rotor 13b which is rotatably placed around the stator 13a, and a
rotary disc 13c which couples the rotor 13b to the stator 13a.
[0032] The cabinet 10 has an inlet opening 14 at a front part
thereof. The inlet opening 14 of the cabinet 10 is aligned with
both the inlet opening 11b of the water tub 11 and the inlet
opening 23 of the rotary drum 20, thus allowing a user to put
laundry into the rotary drum 20 or take the laundry out of the
rotary drum 20 through the three aligned inlet openings 14, 23 and
11b. A door 15 is mounted to an edge of the inlet opening 14 so as
to close the opening 14. To prevent a leakage of the wash water
from the water tub 11, a cylindrical bellows 16 extends between the
inlet opening 14 of the cabinet 10 and the inlet opening 11b of the
water tub 11. A cylindrical guide unit 17 is placed inside the
bellows 16 to allow the user, who stands outside the inlet opening
14 of the cabinet 10, to easily put the laundry into the rotary
drum 20 or take the laundry out of the rotary drum 20.
[0033] A detergent supply unit 18 and a water supply unit 30 are
installed in the cabinet 10 at positions above the water tub 11 to
respectively feed each of a detergent and water into the water tub
11. The detergent supply unit 18 is placed at the front part of the
cabinet to allow the user to easily feed the detergent into the
water tub 11. The water supply unit 30 comprises a first water feed
pipe 32 which extends from an external water supply pipe 31 to the
detergent supply unit 18, a second water feed pipe 33 which extends
from the detergent supply unit 18 to the water tub 11, and a first
control valve 34 which is mounted to an intermediate portion of the
first water feed pipe 32 to control a flow of the water to be fed
into the water tub 11. Due to the coupled construction of the
detergent supply unit 18 and the water supply unit 30, the water
passes through the detergent supply unit 18, prior to reaching the
water tub 11. Therefore, the detergent contained in the detergent
supply unit 18 is fed into the water tub 11 in a state dissolved in
the water.
[0034] The drum washing machine has a heater 40 that is placed in a
lower portion of the water tub 11 so as to heat the water contained
in the water tub 11. A heater holding part 41, which is a
pan-shaped part, is provided at a lower portion of a sidewall of
the water tub 11 by drawing the lower portion of the sidewall of
the tub 11 downward, as shown in FIGS. 1, 2 and 3. The heater 40 is
installed in the heater holding part 41 in which a predetermined
amount of water is collected to a level to allow the heater 40 to
be submerged into the water. Since the heater 40 is placed in the
heater holding part 41 having a pan-shaped appearance, the rotary
drum 20 is rotated without interfering with the heater 40.
[0035] The drum washing machine also has a drain unit 50 and a
water circulation unit 60. The drain unit 50 discharges the water
from the water tub 11 to an outside of the tub 11. The water
circulation unit 60 feeds the water, which is heated by the heater
40 in the water tub 11, into the rotary drum 20. The drain unit 50
comprises a first drain pipe 51, a drain pump 52, and a second
drain pipe 53. The first drain pipe 51 is connected to a drain port
42 which is provided at the heater holding part 41 of the lower
portion of the water tub 11, thus discharging the water from the
water tub 11 to the outside of the tub 11. The drain pump 52 is
mounted to an intermediate portion of the first drain pipe 51. The
second drain pipe 53 extends from an outlet of the drain pump 52.
The water circulation unit 60 includes a second control valve 61, a
water circulation pipe 62, and a spray nozzle 63. The second
control valve 61 is mounted to an intermediate portion of the
second drain pipe 53 that extends from the outlet of the drain pump
52. The water circulation pipe 62 extends from the second control
valve 61 to the inlet opening 23 of the rotary drum 20. The spray
nozzle 63 is mounted to an outlet of the water circulation pipe 62.
The second control valve 61 controls a flow direction of the wash
water flowing from the outlet of the drain pump 52 so as to drain
the discharged wash water to an outside of the cabinet 10 or to
guide the discharged wash water into the water circulation pipe 62.
A motorized three-way valve may be used as the second control valve
61. The spray nozzle 63 is held by the guide unit 17 which is
placed adjacent to the inlet opening 23 of the rotary drum 20, thus
spraying the wash water into the rotary drum 20 through the inlet
opening 23. Due to the above-described coupled construction of the
drain unit 50 and the water circulation unit 60, the water which is
discharged from the lower portion of the water tub 11 may be
drained to the outside of the cabinet 10 or be sprayed into the
rotary drum 20. That is, when the drain pump 52 is operated with
the second control valve 61 controlled to guide the discharged
water to the water circulation pipe 62, as shown in FIG. 1, the
discharged water passes through both the first drain pipe 51 and
the water circulation pipe 62 to be sprayed into the rotary drum
20. However, when the drain pump 52 is operated with the second
control valve 61 controlled to guide the discharged water to the
second drain pipe 53, as shown in FIG. 2, the discharged water is
drained to the outside of the cabinet 10.
[0036] As shown in FIGS. 4 and 5, the rotary drum 20, which is
installed in the water tub 11 to be inclined relative to the
horizontal axis of the cabinet 10 at the first angle a of
inclination, comprises the front part 22 having the inlet opening
23, the rear part 21 securely coupled to the rotating shaft 12, and
a cylindrical sidewall part 24 extending between the front part 22
and the rear part 21. The rotary drum 20 is completely closed along
a junction between the rear part 21 and the cylindrical sidewall
part 24 so as to contain the water in the drum 20. An inner
diameter of the cylindrical sidewall part 24 of the rotary drum 20
gradually increases along a direction from the rear part 21 to the
front part 22, thus allowing an internal surface of the cylindrical
sidewall part 24 of the rotary drum 20 to be inclined relative to
the rotating axis A of the rotary drum 20 at a predetermined second
angle .beta. of inclination. A plurality of drain holes 25 are
provided along an edge of the inlet opening 23 of the front part 22
to discharge the water from the rotary drum 20 to an outside of the
rotary drum 20 through the drain holes 25 when the rotary drum 20
is rotated at a high speed. As shown in FIG. 3, the rotary drum 20
also has a plurality of lifters 26 around an internal surface of
the cylindrical sidewall part 24, thus repeatedly moving the
laundry upward along with the water to drop the laundry and wash
water from the top to the bottom inside the rotary drum 20 due to
gravity, when the rotary drum 20 is rotated in the water tub 11. To
enhance the washing effect of the drum washing machine, a plurality
of agitating blades 27 are provided on an internal surface of the
rear part 21 of the rotary drum 20.
[0037] Since the rotary drum 20 is installed such that the rotating
axis A of the rotary drum 20 is inclined relative to the horizontal
axis of the cabinet 10 at the first angle a of inclination, a
predetermined amount of water is contained in the rotary drum 20 to
allow the laundry to be sunk into the water. The water is fed into
the rotary drum 20 to reach a level that is not higher than a
lowermost drain hole 25 of the rotary drum 20. The first angle a of
inclination of the rotating axis A of the rotary drum 20 relative
to the horizontal axis of the cabinet 10 may be set to
approximately 15.degree. in order to contain an appropriate amount
of water in the rotary drum 20 and effectively wash the
laundry.
[0038] As described above, the internal surface of the rotary drum
20 is inclined relative to the rotating axis A of the rotary drum
20 at the second angle .beta. of inclination, and the drain holes
25 are provided along the edge of the inlet opening 23 of the front
part 22 of the rotary drum 20. As a result, the water is guided to
the drain holes 25 of the rotary drum 20 during a rotation of the
rotary drum 20. That is, when the rotary drum 20 is rotated at a
high speed during a spin-drying operation of the washing machine,
the water is squeezed out of the laundry in the rotary drum 20 to
move outward in a radial direction of the rotary drum 20 due to a
centrifugal force, and is guided to the drain holes 25 provided on
the front part 22 of the rotary drum 20 along the inclined internal
surface of the cylindrical sidewall part 24, prior to being
discharged to the outside of the rotary drum 20. To allow a smooth
discharging of the water from the rotary drum, the second angle
.beta. of inclination of the internal surface of the rotary drum 20
relative to the rotating axis A of the rotary drum 20 may be set at
0.5.degree. or higher.
[0039] FIGS. 6 and 7 are sectional views of a rotary drum 20, with
drain holes provided on the rotary drum 20 according to a first
modification and a second modification of the embodiment of FIG. 1,
respectively. In the first modification of FIG. 6, a plurality of
rows of drain holes 25a are provided on the front part 22 of the
rotary drum 20 along the edge of the inlet opening 23 and drain
holes 25b are provided around an edge of the cylindrical sidewall
part 24 adjacent to the front part 22. Due to the drain holes 25a
and 25b, the rotary drum 20 of FIG. 6 more effectively discharges
the water to the outside thereof, in comparison with the rotary
drum 20 of FIG. 4.
[0040] In the second modification of FIG. 7, the rotary drum 20 is
rounded along a junction corner 28 between the front part 22 and
the cylindrical sidewall part 24, with a plurality of drain holes
25c being formed along the rounded junction corner 28. The rotary
drum 20 of FIG. 7 may be reduced in a water draining effect
thereof, in comparison with the rotary drum 20 of FIG. 6. However,
the rotary drum 20 of FIG. 7 may desirably contain a large amount
of water therein, without enlarging the angle .alpha. of
inclination of the rotary drum 20 relative to the horizontal axis
of the cabinet 10.
[0041] The drum washing machine having the above-mentioned
construction is operated as follows.
[0042] To execute a washing operation, the washing machine is
turned on after laundry is put into the rotary drum 20 and a
detergent is contained in the detergent supply unit 18. When the
washing machine is turned on as described above, the first control
valve 34 of the water supply unit 30 is opened to feed water into
the water tub 11. When the water is fed into the water tub 11, the
water passes through the detergent supply unit 18 prior to reaching
the water tub 11, due to the coupling of the detergent supply unit
18 and the water supply unit 30. Therefore, the detergent contained
in the detergent supply unit 18 is fed into the water tub 11 while
being dissolved in the water. After a predetermined amount of water
is fed into the water tub 11, the supply of water into the water
tub 11 is stopped. Since both the rear part 21 and the cylindrical
sidewall part 24 of the rotary drum 20 as well as the junction
between the rear part 21 and the sidewall part 24 are completely
closed, the water is not introduced into the rotary drum 20 during
the supply of the water into the water tub 11, but the water is
contained in the heater holding part 41 provided at the lower
portion of the sidewall of the water tub 11. In addition, since it
is not necessary to feed the water into the water tub 11 to a level
allowing the laundry in the rotary drum 20 to be submerged into the
water, as in the conventional drum washing machine, the amount of
water required to wash the laundry is substantially reduced.
[0043] When the predetermined amount of water is completely fed
into the water tub 11, the heater 40 is turned on to heat the
water. Since the amount of water contained in the water tub 11 is
reduced, in comparison to the conventional drum washing machine, as
described above, it is possible to quickly heat the water within a
short period, thereby shortening the washing time and reducing an
amount of electricity required to heat the water.
[0044] After the water in the water tub 11 is completely heated by
the heater 40 to a predetermined temperature, the control valve 61
of the water circulation unit 60 is operated to permit the outlet
of the drain pump 52 to communicate with the water circulation pipe
62. When the drain pump 52 in the above state is operated, the
heated water is discharged from the heater holding part 41 to pass
through both the first drain pipe 51 and the water circulation pipe
62, thus being fed into the rotary drum 20. In the above state, an
entire part of the laundry contained in the rotary drum 20 is
uniformly wet with the water since the spray nozzle 63 sprays the
water onto the laundry. The rotary drum 20 is rotated at a low
speed by the motor 13 simultaneously with the spraying of the water
into the rotary drum 20, thus washing the laundry.
[0045] During the washing operation, the entire laundry contained
in the rotary drum 20 is sufficiently wet with the water that is
contained in the rotary drum 20 since the rotary drum 20 is
installed in the cabinet 10 to be inclined relative to the
horizontal axis of the cabinet 10 at the first angle .alpha. of
inclination, as shown in FIG. 1. The drum washing machine thus
smoothly and effectively executes the washing operation. When the
level of the water in the rotary drum 20 exceeds the height of a
lowermost drain hole 25 of the rotary drum 20 during the washing
operation, the water overflows from the rotary drum 20 into the
water tub 11 through the drain holes 25, prior to returning from
the water tub 11 to the rotary drum 20 by an operation of the drain
pump 52. The circulation of the water is continued during the
washing operation. When the drum washing machine performs in the
washing operation, most of the water is continuously fed from the
water tub 11 into the rotary drum 20, so that the water tub 11
contains only a small amount of water therein.
[0046] When the washing operation is finished, the drum washing
machine executes a rinsing operation to repeatedly rinse and
spin-dry the washed laundry. To execute the rinsing operation, the
washed laundry must be primarily spin-dried. To spin-dry the washed
laundry, the drain pump 52 is operated with the second control
valve 61 controlled to permit the outlet of the drain pump 52 to
communicate with the second drain pipe 53, and the rotary drum 20
is rotated at a high speed, thus spin-drying the washed laundry.
While the rotary drum 20 is rotated at a high speed to spin-dry the
laundry, the water is primarily squeezed out of the laundry in the
rotary drum 20 to move radially outward to the internal surface of
the cylindrical sidewall part 24 of the rotary drum 20 due to a
centrifugal force, and is secondarily guided to the drain holes 25
provided on the front part 22 of the rotary drum 20, since the
internal surface of the rotary drum 20 is inclined relative to the
rotating axis A of the rotary drum 20 at the second angle .beta. of
inclination, as shown in FIG. 2. The water in the rotary drum 20 is
thus discharged to the outside of the rotary drum 20 through the
drain holes 25, and the water in the water tub 11 is drained to the
outside of the cabinet 10 by the operation of the drain pump 52.
After spin-drying the washed laundry, new water enters the water
tub 11 by the operation of the water supply unit 30, and is
introduced into the rotary drum 20 by the operation of the water
circulation unit 60, in the same manner as that described for the
washing operation, thus rinsing the laundry. During the rinsing
operation, the spin-drying of the laundry and the feeding of new
water into the water tub 11 are repeated several times.
[0047] The rinsing operation is ended with a final spin-drying of
the rinsed laundry. To finally spin-dry the rinsed laundry, the
drain pump 52 is operated with the second control valve 61
controlled to permit the outlet of the drain pump 52 to communicate
with the second drain pipe 53, and the rotary drum 20 is rotated at
high speeds for a predetermined period of time. That is, the final
spin-drying of the rinsed laundry is performed in the same manner
as an intermediate spin-drying of the laundry during the rinsing
operation.
[0048] The present invention provides a drum washing machine in
which a rotary drum is installed in a cabinet to be inclined
relative to a horizontal axis of the cabinet, and both a rear part
and a sidewall part of the rotary drum as well as a junction
between the rear part and the sidewall part are completely closed.
Water is contained in the rotary drum during a washing operation of
the drum washing machine. Therefore, the drum washing machine uses
less water to wash laundry, without reducing the washing effect as
in the conventional drum washing machines.
[0049] In addition, the drum washing machine feeds a small amount
of water from a water tub into the rotary drum after heating the
small amount of water by use of a heater, thus reducing an amount
of electricity required to heat the water, and reducing the washing
time. Since the drum washing machine uses less water to wash
laundry, the washing machine quickly feeds and drains the water
into and from the water tub, thus reducing the overall washing
time.
[0050] Since the drum washing machine washes the laundry by use of
the less water as described above, the washing machine drains less
water, thus reducing the amount of wastewater causing environmental
pollution.
[0051] Furthermore, the rotary drum of the drum washing machine
does not have spin-drying perforations on the rear part or the
sidewall part thereof, therefore resulting in a simple construction
thereof.
[0052] Although a few embodiments of the present invention have
been shown and described, it would be appreciated by those skilled
in the art that changes may be made in these embodiments without
departing from the principles and spirit of the invention, the
scope of which is defined in the claims and their equivalents.
* * * * *