GB2285063A

GB2285063A - An electric washing machine

Info

Publication number: GB2285063A
Application number: GB9424236A
Authority: GB
Inventors: Shinichi Nakamura; Hideo Akutsu; Shinsuke Ise; Masaji Kukino; Yoshio Yoshida; Norihiko Ishikawa; Takeshi Sugino; Takeshi Saito
Original assignee: Nihon Kentetsu Co Ltd; Mitsubishi Electric Corp
Current assignee: Nihon Kentetsu Co Ltd; Mitsubishi Electric Corp
Priority date: 1993-12-24
Filing date: 1994-11-30
Publication date: 1995-06-28
Anticipated expiration: 2014-11-30
Also published as: GB9424236D0; HK1000291A1; GB2285063B; KR950018821A

Abstract

An electric washing machine enhances washing power by rotating not only the rotary wing (4) but also the washing tub (3). Also, the washing tub has a fixed mode wherein the washing tub is fixed and a free rotation mode wherein the washing tub rotates freely at washing or rinsing process. The tub shaft is driven by a motor through a planet mechanism a clutch and a brake drum around the planet mechanism. The fixed mode of the tub is established by locking the brake drum whilst the free rotation mode is established through the planet gearing but with the clutch separated. <IMAGE>

Description

"AN ELECTRIC WASHING MACHINE" The invention relates to an electric washing machine, in particular, to an electric washing machine for combining a fixed mode wherein the washing tub is fixed and a free rotation mode wherein the washing tub rotates freely at washing or rinsing process.

As well known in the art, an electric washing machine comprises, for example, a water tub 2 arranged inside a casing 1, a washing tub 3 arranged inside the casing 1 and a rotary wing 4 such as a bar shape agitator which i8 protruding at the centre of the washing tub, as shown in Figure 24 of the attached drawings.

A motor 5 is arranged under the water tub 2.

The driving shaft of the motor 5 is coupled to a rotary wing shaft 9 through a pulley 6, a V belt 7, a pulley 8 and further coupled to a washing tub shaft 10 through a spring clutch mechanism 11. The rotary wing shaft 9 is coupled to the rotary wing 4 through a rotation reduction mechanism 12 using a planet gear. The washing tub shaft 10 is coupled to the washing tub 3.

In a washing or rinsing process, the rotary wing shaft 9 rotates in a low speed using the rotation reduction mechanism 12 having a planet gear and the washing tub shaft 10 is separated from a driving shaft of the motor 5 by the spring clutch mechanism 11 80 that the washing tub shaft 10 does not rotate.

In this case, for example, as shown in Laid-Open Japanese Patent Publication No 63-135197, the electric washing machine which switches the states for engagement and separation between the washing tub shaft 10 and the driving shaft of the motor 5 by the spring clutch mechanism 11 includes a lock lever which operates in relation with the operation of the spring clutch mechanism 11. This lock lever engages the brake wheel for stopping the washing tub 3.

According to a feature of planet gear, when the rotary wing shaft 9 rotates in washing process, the washing tub shaft 10 rotates to some extent too.

The lock lever however engages the brake wheel to prevent the rotation of the washing tub 3.

As mentioned above in connection to the conventional electric washing machine, only the rotary wing 4 rotates and the washing tub 3 completely stops at washing or rinsing process. Therefore, it is difficult to provide a sufficient washing power because the water flow for washing is provided only from the rotary wing 4. Since the conventional electric washing machine comprises a rotary wing shaft 9 and a washing tub shaft 10 which are coupled to a driving shaft of a motor 5 through a pulley 6, V belt 7 and pulley 8, lots of parts are necessary. Also there is some fears that the rotation of the motor 5 is not smoothly transferred to the rotary wing shaft 9 and the washing tub shaft 10.

It is an object of the present invention to eliminate an inconvenience of the conventional art, and to provide an electric washing machine for enhancing washing power by rotating not only the rotary wing but also the washing tub.

Further, it is another object of the present invention to provide a electric washing machine for smoothingly transferring the rotation power of motor to the rotary wing shaft and the rewatering shaft by simplifying mechanism for rotating the rotary wing shaft and the rewatering shaft.

In order to obtain the above object, an electric washing machine arranging a rotary wing inside the washing tub of the present invention comprises a combination means for combining a fixed mode wherein the washing tub is fixed and a rotation free mode wherein the washing tub rotates freely at washing or rinsing process.

The rotary wing and a washing tub may rotate toward reverse directions.

The electric washing machine having a rotary wing inside the washing tub of the present invention may comprise a driving shaft of the motor coupled to a rotary wing shaft and also to a washing tub shaft through a clutch mechanism, the washing tub shaft being coupled to the washing tub, and the rotary wing shaft being coupled to a rotary wing through a rotation reduction mechanism using a planet gear.

A rotary tub motor and a washing tub motor may be separately arranged, a driving shaft of the rotary tub motor being coupled to a rotary wing shaft which is coupled to a rotary wing, and a driving shaft of a washing tub motor being coupled to a washing tub shaft which is coupled to the washing tub.

The machine may comprise a lower rotary wing shaft for being coupled directly to the motor, a washing tub shaft being coupled to the lower rotary wing shaft through a clutch mechanism, an upper rotary wing shaft being coupled to the lower rotary wing shaft through a rotation reduction mechanism using a planet gear, a rotary wing for being coupled to the upper rotary wing shaft and a washing tub shaft for being coupled to the washing tub.

The clutch may be a disc clutch constituted of a drum and a disc.

The rotary wing shaft of the washing tub shaft may be coupled coaxially and serially toward length direction for the motor.

The machine may comprise an upper rotary wing shaft which is coupled to a rotary wing in a washing tub coupled to a lower rotary wing shaft through a rotation reduction mechanism using a planet gear, the lower rotary wing shaft being coupled to a motor, a lower washing tub shaft arranged coaxially around the lower rotary wing shaft, the lower washing tub shaft being coupled to the lower rotary wing shaft through clutch apparatus, the lower washing tub shaft being coupled to an upper washing tub shaft through the brake drum which is arranged around the planet gear. The combination means combine a fixed mode wherein the electric washing machine is fixed by fixing a brake drum and a free rotation mode wherein the washing tub rotates freely through a planet gear without fixing the brake drum by separating a clutch at washing or rinsing process.

The fixed mode and the rotation free mode for fixing and rotating the washing tub respectively may be selectable according to contents or kinds of clothing.

The rotation angle of the washing tub at the free rotation mode for freely rotating the washing tub may be controlled so as to be less than a predetermined angle.

A circulating water channel may be arranged in the washing tub for circulating washing water in the washing tub by pumping up the water from a bottom part of the tub to an upper part, the pumping up is carried out in case of fixed mode and free rotation mode.

The machine may comprise a lint removing means allowing a rotary wing to operate less than the range of rotation angle of 3600, and water is additionally supplied up to a water level where circulating water is obtained by pumping up at washing or rinsing process.

The selection of the fixed mode and the free rotation mode for fixing and rotating the washing tub respectively may be carried out using washing operation switch by user.

The washing tub may rotate in a free rotation mode after dewatering process is completed.

The washing tub in the free rotation mode may be switched toward a reverse direction by a short time repetition.

Water may be supplied during an inertia rotation of the washing tub in the free rotation mode after dewatering process is completed which is carried out before rinsing.

The free rotation mode may be automatically switched to the fixed mode when a cover of the washing tub is opened during operation in the free rotation mode for rotating the washing tub.

The control of the washing tub may be carried out by controlling on-off time of voltage supplied to the motor according to detection of rotation angle of the washing tub, or by controlling rotation angle of the motor.

The clutch apparatus may comprise a clutch spring which is wound around the lower washing tub shaft and the lower rotary wing shaft, one end of the clutch spring wound around the lower washing tub shaft side is fixed at the end of the one clutch gear case which covers half of the clutch spring and another end of the clutch spring wound around the lower rotary wing shaft side is fixed at the end of the other clutch gear case which covers the other half of the clutch spring, each clutch gear which is arranged outer surface of each clutch gear case engaged clutch pieces, respectively so that they can engage or separate freely.

The clutch may have two clutch pieces at the upper and bottom which engage respective clutch gears, and the brake band simultaneously fastens the brake drum during the fixed mode for fixing the washing tub, and the two clutch pieces at the upper and bottom engage respective clutch gears, and the brake band simultaneously loosens the brake drum during the rotation free mode for rotating the washing tub freely.

With the present invention, a differential factor (= rotation speed of the washing tub 9 rotation speed of the rotary wing) may be selected to be substantially less than 0.5 during the free rotation mode for rotating the washing tub freely.

In the clutch, the clutch pieces may engage the clutch gear or separate from the clutch gear by a lever operated by an actuator, and the lever be coupled to a brake band which is wound around the outer periphery of a flange arranged around the planet gear.

A washing and dewatering tub may be substituted for a washing tub, with a water tub being arranged around the washing and dewatering tub with a drain outlet draining the water out of the water tub for the dewatering process.

In the clutch, a clutch spring may be wound around a lower washing tub shaft and a lower rotary wing shaft which is protruding under the lower washing tub shaft. In that case, the clutch spring is covered by respective two clutch gear cases at the lower washing tub shaft side and at the lower rotary wing shaft side, each clutch gear is arranged around the surface of each clutch gear case, each end of the clutch spring is fixed at each inside wall of each clutch gear case, each clutch gear engages each clutch piece or separates from each clutch piece, the clutch piece is arranged at the tip of the lever which operates by on-off voltage supply to the actuator, the lever is coupled to the brake band wound around the outer periphery of the brake drum which is arranged around the planet gear, wherein the washing operation is carried out by engaging the two clutch pieces at the upper and bottom to respective clutch gears and simultaneously fastening the brake drum, or by engaging the two clutch pieces at the upper and bottom to respective clutch gears and simultaneously loosening the brake drum, and the dewatering operation is carried out by separating the two clutch pieces at the upper and bottom from respective clutch gears and simultaneously loosening the brake drum.

An operation for engaging the two clutch pieces at the upper and bottom to respective clutch gears and simultaneously fastening the brake drum may be carried out by on-off operation of the voltage supply to the actuator.

The invention will be further described by way of non-limitative example, with reference to the accompanying drawings, in which: FIG. 1 is a cross-sectional view showing an electric washing machine of a first embodiment of the present invention.

FIG. 2 is a longitudinal cross-sectional view showing a main portion of a driving apparatus of an electric washing machine of a first embodiment of the present invention.

FIG. 3 is a exploded perspective view showing a main driving apparatus of an electric washing machine of a first embodiment of the present invention.

FIG. 4 is a perspective view showing a main portion of a driving apparatus of an electric washing machine of a first embodiment of the present invention.

FIG. 5 is a perspective view showing an example of disc clutch of an electric washing machine of a first embodiment of the present invention.

FIG. 6 is another perspective view showing an example of disc clutch of an electric washing machine of a first embodiment of the present invention.

FIG. 7 is also another perspective view showing an example of disc clutch of an electric washing machine of a first embodiment of the present invention.

FIG. 8 shows a finishing degree of washing of an electric washing machine of a first embodiment of the present invention.

FIG. 9 is a cross-sectional view showing an electric washing machine of a second embodiment of the present invention.

FIG. 10 is a cross-sectional view showing main portion of an electric washing machine of a second embodiment of the present invention.

FIG. 11 is a cross-sectional view showing an electric washing machine of a third embodiment of the present invention.

FIG. 12 is a longitudinal cross-sectional view showing a clutch apparatus of an electric washing machine of a third embodiment of the present invention FIG. 13 is a partially notched side view of a clutch apparatus of an electric washing machine of a third embodiment of the invention.

FIG. 14 is a exploded perspective view showing a clutch apparatus of an electric washing machine of a third embodiment of the present invention.

FIG. 15 is a bottom view showing a clutch apparatus of electric washing machine of a third embodiment of the present invention.

FIG. 16 is a bottom view showing a clutch apparatus of electric washing machine of a third embodiment of the present invention for explaining a fixed mode where the rotary wing is rotating and the washing tub is fixed during washing or rinsing processes.

FIG. 17 is a bottom view showing a clutch apparatus of electric washing machine of a third embodiment of the present invention for explaining a rotation free mode where the rotary wing and the washing tub are rotating freely during washing or rinsing processes.

FIG. 18 is a bottom view showing a clutch apparatus of electric washing machine of a third embodiment of the present invention for explaining a dewatering process where the rotary wing and the washing tub are rotating in a high speed during dewatering process.

FIG. 19 shows a characteristic curve illustrating a differential factor during an operation of electric washing machine of a third embodiment of the present invention.

FIG. 20 shows a characteristic curve illustrating a relation between rotation speed of a motor fo, rotation speed of a rotary wing fp, and rotation speed of a washing tub fD and differential factor versus washing load of electric washing machine of a third embodiment of the present invention.

FIG. 21 illustrates a washing process during an operation of an electric washing machine of a third embodiment of the present invention.

FIG. 22 shows a characteristic curve illustrating a relation between dirt removing efficiency, washing deflection and differential factor during an operation of an electric washing machine of a third embodiment of the present invention.

FIG. 23 illustrates a rinsing process during an operation of an electric washing machine of a third embodiment of the present invention.

FIG. 24 is a cross-sectional view showing a conventional electric washing machine.

Embodiment 1 A first embodiment of the present invention is explained in detail using figures as follows. FIG. 1- FIG. 7 shows an electric washing machine of a first embodiment of the present invention. As is the same as the conventional electric washing machine explaining already in FIG. 24, the basis construction of the present invention arranges a water tub 2 inside the casing 1, a washing tub 3 inside a water tub 2 and rotary wing 4 such as agitator or pulsator inside the washing tub 3. FIG. 2 is a longitudinal cross-sectional view showing a main portion of a driving apparatus of an electric washing machine of a first embodiment of the present invention. FIG.

3 is a exploded perspective view showing a main driving apparatus of an electric washing machine of a first embodiment of the present invention.

In the figures, the motor 5 is arranged under the water tub 2, the motor 5 is coupled directly to the lower part of lower rotary wing shaft 9a, the lower rotary wing shaft 9a is supported by a radial ball bearing 18, a main bearing 19 through an oil impregnation metal seal 17. The upper portion of the lower rotary wing shaft 9a is coupled to a sun gear, that is high speed side of the rotation reduction mechanism 12 using a planet gear.

Then, the lower part of the upper rotary wing shaft 9b is coupled to a low speed side of the rotation reduction mechanism 12, the upper portion of the upper rotary wing shaft 9b is coupled to the rotary wing 4.

Then, the washing tub shaft 10 is coupled to the lower rotary wing shaft 9a through a disc clutch mechanism 13. The disc clutch mechanism 13 comprises a drum 14 and a disc 15 which is located above the drum 14. The drum 14 is supported by a radial ball bearing 20. In the figure, the numerical number 21 shows a bearing cover of the radial ball bearing 20.

FIG. 4 is a perspective view showing a main driving apparatus of an electric washing machine of a first embodiment of the present invention. The washing tub shaft 10 is arranged coaxially outside of the upper rotary wing shaft 9b through an oil impregnation metal seal 22, and supported by a main bearing 24 through the radial ball bearing. Then, a flange 25 coupled to the lower portion of the washing tub shaft 10 is coupled to the disc 15 comprised of the disc clutch mechanism 13. An operation member 26 arranged at a lower portion of the drum 14 is connected to a torque motor 16 in order to engage the drum 14 to the disc 15 as shown in FIG. 4.

FIG. 5 is a perspective view showing an example of disc clutch of an electric washing machine of a first embodiment of the present invention. FIG.

6 is another perspective view showing an example of disc clutch of an electric washing machine of a first embodiment of the present invention. FIG. 7 is also another perspective view showing an example of disc clutch of an electric washing machine of a first embodiment of the present invention.

Shapes of the drum 14 and disc 15 of the disc clutch mechanism 13 may be radial tooth forms 14a, 15a, respectively, such as in FIG. 5, flat board shapes such as in FIG. 6, or a protruding portion 14b formed on the drum 14 and corresponding groove shape formed on the disk 15 such as in FIG. 7.

Many various kinds of shapes may be used for this engagement.

The disc 15 is separated from the drum 14 in the disc clutch mechanism 13 in washing or rinsing process, and rotation power of the motor 5 is not transferred to the washing tub shaft 10, that is, a free state. Then the lower rotary wing shaft 9a rotates reversely according to the reverse rotation of the motor 5. In this case, rotation speed of the lower rotary wing shaft 9a is decreased by the rotation reduction mechanism 12 using a planet gear and transferred to the upper rotary wing shaft 9b. This upper rotary wing shaft 9b rotates at a low speed, which allow the rotary wing 4 to rotate slowly.

At a washing process, when a large load is applied to the rotary wing 4 by some reasons such as tangle of washing in the washing tub 3 onto the rotary wing 4, from the feature of planet gear, the upper rotary wing shaft 9b which is a free state and the washing tub shaft 10 coupled to the washing tub 3 rotate reversely against the rotary wing 4.

Thus, swirl flow is generated inside the washing tub 3 by the rotary wing 4, and at the same time other reverse swirl flow is generated outside of the washing tub 3 and then the clothing is crumpled and washed. Therefore, it is apparent that finishing degree of washing increases when both the rotary wing 4 and the washing tub 3 rotate as shown in FIG. 8.

When clothing is taken out from the washing tub 3 after the washing is completed, user can freely rotate or change the direction of the washing tub 3 by hand for taking out the clothing easily, because the washing tub 3 is in a free state without locking as in the prior electric washing machine.

In dewatering process, the operation member 26 is raised by the torque motor 16, the drum 14 engages the disc 15, rotation power of the lower rotary wing shaft 9a is transferred to the washing tub shaft 10 through this disc clutch mechanism 13, the portion of the upper rotary wing shaft 9b is coupled directly to the lower rotary wing shaft 9a, then the upper rotary wing shaft 9a and the lower rotary wing shaft 9b and also the washing tub shaft 10 rotates toward one direction in a high speed.

Embodiment 2 FIG. 9 shows a second embodiment of electric washing machine of the present invention. As shown in this figure, a rotary tub motor 28 and washing tub motor 27 are arranged separately under the water tub 2, the driving shaft of the rotary tub motor 28 is coupled to the a rotary wing shaft 9 through a pulley 31, a V belt 32, and a pulley 33, the driving shaft of the washing tub motor 27 is coupled to the washing tub shaft 10 through a pulley 34, a V belt 35, and a pulley 36. The above construction causes the rotary wing 4 and the washing tub 3 to rotate toward the reverse direction at washing or rinsing process.

As explained above, in washing process, the rotary tub motor 28 and the washing tub motor 27 rotate toward reverse direction, respectively.

Respective rotation powers are transferred to the rotary wing shaft 9 and the washing tub shaft 10, which cause the rotary wing 4 and the washing tub 3 to rotate toward reverse direction, respectively. FIG. 10 is a cross-sectional view showing pulley portion of an electric washing machine of a second embodiment of the present invention.

Embodiment 3 FIG. 11 - FIG. 23 shows a third embodiment of electric washing machine of the present invention. FIG. 11 is a cross-sectional view showing an electric washing machine of a third embodiment of the present invention. In FIG. 11, a rotary wing 4 such as an agitator or a pulsator ( FIG. 11 shows a pulsator) is arranged in the washing tub 3 inside, a circulating water channel 40 is formed under the rotary wing 4 and between the bottom and top of the washing tub 3, an discharge opening 41 of the circulating water channel 40 opens under a portion of a balancer 42. The circulating water channel 40 is formed as protruded from surface to inside of the washing tub 3. Buffuls 43 is also formed as a protruded portion on the surface of the circulating water channel 40 inward of the of washing tub 3.

FIG. 12 is a longitudinal cross-sectional view showing a clutch apparatus of an electric washing machine of a third embodiment of the present invention. A rotation shaft of the motor 5 (in FIG. 11) which is arranged under the water tub 2 is coupled to a fixed drum 44 coupled to the lower rotary wing shaft 9a through a pulley 6 (in FIG. 11), a V belt 7 (in FIG. 11), and a pulley 8. The upper portion of the lower rotary wing shaft 9a is coupled to the upper rotary wing shaft 9b through the rotation reduction mechanism 12 using a planet gear. The upper rotary wing shaft 9b is coupled directly to the rotary wing 4.

The rotation reduction mechanism 12 couples the lower rotary wing shaft 9a to the sun gear 71 which rotates in a high speed. The upper rotary wing shaft 9b is coupled directly to a rotation shaft of the planet gear 72 which engages around the sun gear 71. This rotation shaft rotates in a low speed. An outer ring gear 73 is further arranged outside of planet gear 72.

A lower washing tub shaft 46a is coupled coaxially to the lower rotary wing shaft 9a through a metal seal 45. This lower washing tub shaft 46a is supported at the main bearing 48 through a bearing 47, and coupled to the upper washing tub shaft 46b through a brake drum 39 having the outer ring gear therein.

This upper washing tub shaft 46b is coupled coaxially to the upper rotary wing shaft 9b through metal seal 50, and is supported by an upper main bearing 49 through bearing 51. Numerical number 52 shows a damper seal sealing which seals between the upper main bearing 49 and the upper washing tub shaft 46b.

As shown in FIG. 12, in an electric washing machine, the clutch apparatus comprises a clutch spring 53 which is wound around the lower washing tub shaft 46a and a drum 44 on the lower rotary wing shaft 9a. The upper part of the clutch spring 53 wound around the lower washing tub shaft 46a side and the lower part of the clutch spring 53 wound around the drum 44 are covered separately by a clutch gear case 54 and a clutch gear case 55, respectively.

Upper and lower clutch gear cases 56, 57 are arranged around the clutch gear cases 54, 55, respectively. Upper end portion of the clutch spring 53 is fixed to the inner wall of the upper clutch gear case 54, and lower end portion of the clutch spring 53 is fixed to the inner wall of the lower clutch gear case 55. The upper and the lower clutch gears are installed around the upper and lower clutch gears 56, 57, respectively. Upper and lower clutch pieces 58, 59 engage in or separate from the clutch gears 56, 57, respectively.

FIG. 13 is a partially notched side view of a clutch apparatus of an electric washing machine of a third embodiment of the invention. FIG. 14 is a exploded perspective view showing a clutch apparatus of an electric washing machine of a third embodiment of the present invention. FIG. 15 - FIG. 18 are bottom views showing a clutch apparatus of electric washing machine of a third embodiment of the present invention. In these figures, the clutch pieces 58, 59 which engage the clutch gears 56, 57, respectively, are designed so that they are facing oppositely. The clutch piece 58 prevents the clutch gear 56 from clockwise rotation, the clutch gear 59 prevents the clutch gear 57 from counter clockwise rotation.

The clutch pieces 58, 59 are installed rotatably at a tip of a U shaped arm 60 by a spring 61. A lower edge of a diagonal arm 62 is installed on one end of the U shaped arm 60. An installation piece 63 protruding from the diagonal arm 62 is installed rotatably on the flange portion of the lower main shaft bearing 48. In this case, the installation piece 63 is arranged so that the clutch pieces 58, 59 engage to the clutch gears 56, 57, respectively, by a spring 65 in a normal operation.

On the other hand, a tip of the lever 64 coupled to the actuator 66 by a wire 67 is coupled rotatably to the flange portion of lower main shaft bearing 48. Both ends of brake band 68 wound around the brake drum 39 are fixed near the shaft of lever 64.

In this case, the lever 64 is arranged toward a direction, which fastens the brake band 68 by the spring 69.

A bolt shape bar type member 70 is installed to the installation piece 63.

When the lever 64 moves up its position by the operation of the actuator 66, the lever 64 pushes the bolt shape bar type member 70, which rotates the installation piece 63 toward clockwise direction.

Furthermore, pulling member 38 is installed on the other end of the lever 64 for pulling a drain valve 37 which is installed under the bottom of the water tub 2 as shown in FIG. 1.

An operation of the embodiment is explained. In washing process, two modes are combined. One of them is a fixed mode for fixing the washing tub by fixing the brake drum, and another is a rotation free mode for freely rotating the washing tub without fixing brake drum. In order to freely rotate the washing tub 3 as a rotation free mode, it is possible in such a way for not applying a voltage to the actuator 66. At the time, the lever 64 is positioned as shown in FIG. 15 by the elastic force of spring 69, and the brake band 68 fastens the brake drum 39. The installation piece 63 is also positioned as shown in FIG. 15 by the elastic force of spring 69, the two clutch pieces 58, 59 at the tip of arm 60 engage to the clutch gears 56, 57, respectively.

Therefore, the respective clutch gears 56, 57 rotates toward opposite direction, then both the top and bottom ends of the clutch spring 53 which are fixed to the upper and lower clutch gear cases 54, 55, respectively, are flared.

Accordingly, the fastening force of the clutch spring 53 is not applied to the drum 44 which is engaged to lower rotary wing shaft 9a tightly and the lower washing tub shaft 46a. That is, the clutch spring 53 separates from the surface of the lower rotary wing shaft 9a and the lower washing tub shaft 46a.

Therefore, the lower rotary wing shaft 9a and the lower washing tub shaft 46a are not rotate at the same time.

When voltage is supplied to the motor 5, the rotation power is transferred only to the lower rotary wing shaft 9a through the pulley 6, V belt 7, pulley 8 and drum 44, but not to the lower washing tub shaft 46a. The high speed rotation of lower rotary wing shaft 9a is slowed down by the rotation reduction mechanism 12 using the planet gear and transferred to the upper rotary wing shaft 9b which allows the rotary wing 4 to rotate at a low speed.

Then, although the rotary wing 4 rotates toward reverse direction alternately, since both ends of clutch springs 53 are fixed to the clutch gear cases 55, 56, respectively, if the lower rotary wing shaft 9a rotates to any right or left direction, the clutch spring 53 is not fastened by the lower rotary wing shaft 9a. Therefore, the rotary wing 4 rotate smoothly toward the reverse direction.

In this state, from a feature of the planet gear, the upper washing tub shaft 46b and the lower washing tub shaft 46a are apt to rotate toward reverse direction against the rotary wing 4. But, since the brake band 68 fastens the brake drum 39, the rotation of the upper and lower washing tub shafts 46b, 46a is prevented from rotating the washing tub 3. Thus, the washing tub 3 is at the fixed state.

Since the fixed state of the washing tub 3 is carried out at no voltage supply to the actuator 66, the safety is assured even if the electric power supply is interrupted or electric system breaks down, because the fixed state of the washing tub 3 is maintained.

When voltage is supplied to the actuator 66, a wire 67 is pulled up a little bit by the actuator 66 toward the arrow direction as shown in FIG. 15, the lever 64 rotates toward left direction against the force of the spring 69. As a result, the brake band 68 is moderated, and the washing tub 3 becomes rotation free mode where the washing tub 3 can rotate freely.

In this rotation free mode, rotation force of the outer ring gear which is generated by a reactive force of auto-rotation of planet gear which rotates reverse direction to the planet gear. The rotation force is transferred to the upper and lower washing tub shafts 46b, 46a to allow the washing tub 3 to rotate toward reverse direction against the rotary wing 4. In this case, there occurs at the same time further force which allows the washing tub 3 to rotate by the movement of clothing tangled to the rotary wing 4. Therefore, the movement of the washing tub 3 is determined by a resultant force of a rotation force generated by the reactive force of planet gear, and a rotation force generated reversely by the clothing. However, since the rotation force generated by the planet gear is actually far larger than the rotation force generated by clothing, the washing tub 3 rotates toward reverse direction against the rotary wing 4.

The rotation state of the washing tub 3 differs from inertia of a rotation portion of the washing tub 3, resistance of the rotation portion, resistance which the washing tub 3 receives from the clothing and water. The rotation state of the rotary wing 4 differs from inertia around the shaft of the rotary wing 4 such as a pulsator, resistance which the rotary wing 4 receives from the clothing and water. However the rotation state is decided univocally as shown in FIG. 19.

FIG. 16 is a bottom view showing a clutch apparatus for explaining a fixed mode where the rotary wing is rotating and the washing tub is fixed during washing or rinsing processes. FIG. 17 is a bottom view showing a clutch apparatus for explaining a rotation free mode where the rotary wing and the washing tub are rotating freely during washing or rinsing processes.

FIG. 18 is a bottom view showing a clutch apparatus for explaining a dewatering process where the rotary wing and the washing tub are rotating in a high speed during dewatering process.

In the dewatering process of FIG. 16, in, if the lever 64 is further pulled up against elastic force of the spring 69, the state changes to the state of FIG.

18 through the state of FIG. 17. The side of the lever 64 contacts and pushes a tip of the bar type member 70. As a result, the installation piece 63 where the bar type member 70 is installed rotates toward counter clockwise against the elastic force of the spring 65, then the arm 60 which is formed into one body with the installation piece 63 rotates toward left direction and then the clutch pieces 58, 59 separate from the clutch gears 56, 57, respectively.

Then, the clutch spring 53 becomes a free state and it sticks around the lower rotary wing shaft 9a and the lower washing tub shaft 46a. Therefore, the rotation force of the lower rotary wing shaft 9s transferred to the lower washing tub shaft 46a, thus the upper rotary wing shaft 9b is coupled directly to the lower rotary wing shaft 9a. Accordingly, the rotary wing 4 and the washing tub 3 simultaneously rotate in a high speed.

When the lever 64 rotates toward left to direction shown in FIG. 16, the pulling member 38 one end of which is connected to the lever 64 is pulled up, and the drain valve 37 installed under the bottom of the water tub 3 is removed and'the water in the washing tab is drained. If supplied voltage to the actuator 66 is cut off, the installation piece 63 and the lever 64 automatically recover to its original state by the elastic force of the springs 65, 69.

FIG. 19 shows a characteristic curve illustrating a differential factor during an operation of electric washing machine of a third embodiment of the present invention. In FIG. 19, assume that differential factor is the rotation speed fD of the washing tub 3 . rotation speed fp of the rotary wing 4, for example, in the case of load B (clothing load is about 5 Kg), the differential factor is approximately 0.18, mean rotation number of the rotary wing 4 is approximately 110 rpm, and the rotation speed of the washing tub 3 is approximately 20 rpm. It is easily understood from FIG. 19 that if rotation speed fp of the rotary wing 4 decreases, the rotation speed fD of the washing tub 3 increases.

FIG. 20 shows a characteristic curve illustrating a relation between rotation speeds fo of a motor, rotation speeds fp of a rotary wing, and rotation speeds fD of a washing tub and differential factor versus clothing load of electric washing machine of the third embodiment of the invention.

In connection with driving the rotary wing 4 and the washing tub 3 in the washing process, rotation state of the rotary wing 4 and the washing tub 3 is automatically determined by a load condition applied to the rotary wing 4 and the washing tub 3. That is, when clothing load gradually increases from zero, the rotation speed fD of the washing tub 3 and the differential factor increases and the rotation speeds fp of a rotary wing decreases. This tendency continues to increase until the clothing load becomes 2 Kg, after then the rotation speed fD of the washing tub 3 and the differential factor decreases and the rotation speeds fp of a rotary wing increases. Therefore, the rotation speeds fp of a rotary wing, the rotation speed fD of the washing tub 3 and the differential factor have a pole around the clothing load of 1 - 2 Kg. The rotation speed of the fo motor decreases gradually according to the increase of the clothing load by the slip of the induction motor.

In this invention, at the rotation free mode for freely rotating the washing tub 3, on-off time for reversing the rotation of the motor 5 is controlled or the motor is controlled according to the detection of rotation angle of the washing tub in order to prevent the rotation angle of the washing tub from to rotate larger than a predetermined value. Thus, the degradation of washing power of the washing machine, and dangerousness according to the excess rotation of the washing tub can be prevented.

FIG. 21 illustrates a washing process during an operation of an electric washing machine of a third embodiment of the present invention. In the present invention, the fixed mode of the washing tub 3 and the rotation free mode of the washing tab are combined appropriately in washing process. The process of FIG. 21 shows one example of the washing process, in which washing water in the washing tub 3 is scooped by the rotation force of the rotary wing 4 through the circulating water channel 40, and the water is discharged again into the washing tab 3 from the upper discharge opening 41.

In this case, a lint electric filter (not shown) is installed at the discharge opening 41.

In the first process " permeating / dissolving detergent", the rotation of the washing tub 3 is set to a rotation free state. In this state, since the washing tub 3 rotates slowly toward reverse direction against the rotary wing 4, the clothing floating on the water surface is stirred by the bufful 43 and permeated early into the water. Then the washing process can be effectively started.

The washing process usually starts by supplying detergent on the washing.

Therefore, if the washing tub 3 is in a rotation free state, the clothing permeates early in the water as described above, and the detergent on the washing sinks melts early and is stirred in the water. Further, the detergent which is spilled between the washing tub 3 and the water tub 2 easily melts, because the water between the washing tub 3 and water tub 2 is stirred by the rotation of the washing tub 3.

In a first half process "dirt removing (washing)" , the washing tub 3 is in the rotation free mode. The clothing is stirred evenly by bufful 43 in the washing tub 3 and the rotary wing 4, which makes the washing process less deflected. At this time, the clothing near the rotary wing 4 moves toward the same direction as that of the rotary wing 4 and is also pushed to the wall of the washing tub 3 by centrifugal force generated by the rotary wing 4. Where, the washing tub 3 rotates toward reverse direction against the rotary wing 4.

Therefore, the washing contacts the inside wall of the washing tub 3, which effectively removes the dirt by the rub on the surface of the clothing.

The washing which is in upper portion of the washing tub 3 is less affected from the rotation of the rotary wing 4 and is rocked toward reverse direction against the rotary wing 4. Therefore, there occurs a torsion toward top and bottom direction to the washing, which gives a crumple effect to fiber for effectively removing the dirt.

If a rotation angle of the washing tub 3 is less than 360 degrees, it gives an appropriate torsion to the clothing for effectively removing the dirt.

Alternatively, when the rotation angle becomes larger than 360 degree, there is a tendency that the clothing is collected centrally. And, if the differential factor becomes larger, a rotation speed fD of the washing tub 3 becomes larger, and the rotation speed fp of the rotary wing 4 becomes adversely lower. Therefore, the same tendency occurs and the efficiency for removing dirt becomes worse.

FIG. 22 shows a relation between dirt removing efficiency, washing deflection and differential factor during an operation of an electric washing machine of a third embodiment of the present invention. As a result of experiment, the dirt removing efficiency, washing deflection, value of cloth tangle are different according to the value of differential factor, and it becomes apparent that there exists optimum value range. That is, if the differential factor is in the range less than 0.5, dirt removing efficiency becomes better, washing deflection become less, and cloth tangle occurs less.

Accordingly, high quality washing can be provided.

In the next cloth circulation process, the washing tab is set in a fixed mode to allow the rotary wing 4 to rotate for a larger rotation angle. In this mode, since the rotary wing 4 causes the clothing to move largely up and down, the washing deflection of the clothing largely decreases.

In a last half process of "dirt removing" there are two stages. In the first stage, the washing tab 3 is set to fixed mode, which enhances the water flow in comparison with the rotation free mode and stubborn dirt can be washed off.

Then in the second stage, the mode of the washing tab is changes to rotation free mode, which causes the washing tub 3 and the rotary wing 4 to rotate toward reverse direction. Therefore, the clothing is stirred evenly and tangle of clothing is unravelled.

In the last unravelling process, the rotary wing 4 rotates for a small rotation angle in the fixed mode. Thus, the washing is stirred forcefully little by little, and the coiled clothing is unravelled fully.

mG. 23 illustrates a rinsing process during an operation of an electric washing machine of a third embodiment of the present invention. In the figure, in a scraping process, the operation of the washing tab is set to rotation free mode, which causes the washing tub 3 and the rotary wing 4 to rotate toward reverse direction. In this process, the washing which has stuck to the inner surface of the washing tub 3 in the preceding dewatering process is tom off. Since this process causes the clothing to stir quickly in the water, the detergent contained in the clothing is diluted. Therefore, the rinse performance can be improved.

In the next stirring (rinse) process, the operation of the washing tab is set to fixed mode which enhances the water flow in comparison with the rotation free mode. Therefore, the detergent contained by clothing begins to be squeezed by a strong stirring. Accordingly, the dilution effect operates appropriately by water newly supplied in the washing tab 3.

In the last unravelling process, the operation of the washing tub is set to a fixed mode, then the rotary wing 4 rotates within a small rotation angle in the fixed mode and the washing is stirred forcefully little by little, and the coiled clothing is unravelled fully in the same way as the washing process.

The combination of the fixed mode and rotation free mode are set in advance, and the selection is carried out by on-off automatic control of the voltage supply to the actuator 66. However, the control is not limited only by the above method. Other combination is of course possible. And, user can select a fixed mode or a rotation free mode voluntarily in considering with degree of clothing quality and dirt by pushing a washing electric switch.

For example, for clothing such as wool, a soft water flow can be provided by setting a rotation free mode, and for washing having stubborn dirt and thick clothing such as Jean, a strong water flow can be provided by setting a fixed mode.

It is possible to provide a lint removing process into the washing and rinsing process in addition to the afore mentioned processes. In this lint removing process, since the rotation angle of the rotary wing 4 less than 360 degrees is provided, clothing is unravelled and the lint stuck to clothing is easily scraped. In this lint removing process, water is supplied up to a level higher than usual level where circulating water is satisfactorily obtained by pumping up from the circulating water channel 40.

In dewatering process, if the lever 64 is further pulled up against elastic force of the spring 69 as shown in FIG. 18, the side of the lever 64 contacts and pushes a tip of the bar type member 70. As a result, the installation piece 63 where the bar type member 70 is installed rotates toward clockwise against the elastic force of spring 65, then the arm 60 which is formed into one body with the installation piece 63 rotates toward clockwise direction and then the clutch pieces 58, 59 separate from the clutch gears 56, 57, respectively.

Then, the clutch spring 53 becomes a free state and it sticks around the drum 44 on the lower rotary wing shaft 9a and the lower washing tub shaft 46a. Therefore, the rotation force of the lower rotary wing shaft 9a is transferred to the lower washing tub shaft 46a, thus the upper rotary wing shaft 9b is coupled directly to the lower rotary wing shaft 9a. Accordingly, the rotary wing 4 and the washing tub 3 simultaneously rotate in a high speed.

Further explanation regarding the spring 53, the drum 44 on the lower rotary wing shaft 9a and the lower washing tub shaft 46a is added for further understanding. In the dewatering process, the upper and lower clutch pieces 58, 59 separate from the clutch gears 56, 57, respectively, the clutch gear cases 54, 55 can move freely. Therefore, if the drum on the lower rotary wing shaft 9a rotates in a fast speed according to the motor rotation, the lower side clutch gear case 55 rotates faster than the upper clutch gear case 54 by the friction between the spring 53 and the drum 44 and the lower washing tub shaft 46a. Therefore, the spring 53 fastens the drum and the lower washing tub shaft 46a, which causes the drum 44 and the lower washing tub shaft 46a to rotate simultaneously.

When the lever 64 rotates toward left to direction shown in FIG. 15, the pulling member 38 one end of which is connected to the lever 64 is pulled up, and the drain valve 37 installed under the bottom of the washing tub 3 is removed and the water in the washing tab is drained.

When there is a rinse process after the dewatering process, a free mode is set after dewatering process. In this process, the clothing which stuck to the inner surface of the washing tub 3 by centrifugal force can be easily torn off and the clothing can be easily unravelled in the next rinse process. Therefore, the rinse performance is improved.

Further, in this process, if the washing tub 3 rotates little by little and if water is supplied simultaneously, the clothing which stuck to the inner surface of the washing tub 3 can be easily torn off, and the clothing contacts the water quickly, therefore, the rinse performance is improved.

By combining a fixed mode with a free rotation mode, it is possible to set a course which is completed in a short time in comparison with the normal courses which are supplied by ordinary course. In this case, it is possible to remove dirt effectively and rinse in a short time. It is convenient, for example, for washing in a hurry before going out.

Furthermore, it is possible to automatically change to the fixed mode, if the cover of the washing tub is opened during operation at the free rotation mode, by linking the voltage supply to actuator 66 so that the power supply is cut off according to the opening of the cover. Therefore, if the cover is open, it is safe because the washing tub 3 is fixed.

The foregoing description is intended to be exemplary. Those skilled in the art will recognise that many modifications to the foregoing description can be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. An electric washing machine having a rotary wing arranged inside a washing tub and comprising mode selection means for selectively fixing the washing tub against rotation in a fixed mode or releasing the washing tub to allow it to rotate freely in a free rotation mode during a washing or rinsing process.

2. An electric washing machine according to claim 1, wherein the rotary wing and the washing tub are rotatable in reverse directions.

3. An electric washing machine according to claim 1 or 2, comprising: a rotary tub motor for rotating the rotary wing and a separate washing tub motor for rotating the washing tub.

4. An electric washing machine according to claim 1 or 2, comprising: a motor having a driving shaft coupled to a rotary wing shaft and also to a washing tub shaft through a clutch mechanism, the washing tub shaft being coupled to the washing tub; and the rotary wing shaft being coupled to a rotary wing through a rotation reduction mechanism using a planet gear.

5. An electric washing machine according to claim 4, comprising: a lower rotary wing shaft coupled directly to said motor; the washing tub shaft being coupled to said lower rotary wing shaft through the clutch mechanism; an upper rotary wing shaft being coupled to the lower rotary wing shaft through the rotation reduction mechanism; and the rotary wing being coupled to the upper rotary wing shaft.

6. An electric washing machine according to claim 4 or 5, wherein said clutch mechanism comprises a disc clutch constituted of a drum and a disc.

7. An electric washing machine according to claim 4, 5 or 6, wherein said rotary wing shaft and the washing tub shaft are coupled coaxially and serially axially of the motor.

8. An electric washing machine according to claim 5, or any claim dependent therefrom, comprising: a lower washing tub shaft arranged coaxially around the lower rotary wing shaft, the lower washing tub shaft being coupled to the lower rotary wing shaft through clutch apparatus, the lower washing tub shaft being coupled to an upper washing tub shaft through a bral;e drum arranged around the planet gear; the mode selection means being operable to select the fixed mode by fixing the brake drum and the free rotation mode by not fixing the brake drum by separating the clutch at washing or rinsing process.

9. An electric washing machine according to claim 8, wherein the clutch apparatus comprises a clutch spring which is wound around the lower washing tub shaft and the lower rotary wing shaft, one end of the clutch spring wound around the lower washing tub shaft side is fixed at the end of the one clutch gear case which covers a half of the clutch spring and another end of the clutch spring wound around the lower rotary wing shaft side is fixed at the end of the other clutch gear case which covers the other half of the clutch spring, each clutch gear which is arranged outer surface of each clutch gear case engages clutch pieces, respectively so that they can engage or separate freely.

10. An electric washing machine according to claim 8 or 9, wherein upper and lower clutch pieces engage respective clutch gears, and the brake band simultaneously fastens the brake drum during the fixed mode for fixing the washing tub, and the two clutch pieces at the upper and bottom engage respective clutch gears, and the brake band simultaneously loosens the brake drum during the free rotation mode for rotating the washing tub freely.

11. An electric washing machine according to claim 9 or 10, wherein the clutch pieces engage the clutch gear or separate from the clutch gear by a lever operated by an actuator, and the lever is coupled to a brake band which is wound around the outer periphery of a flange arranged around the planet gear.

12. An electric washing machine according to claim 8, wherein a clutch spring is wound around a lower washing tub shaft and a lower rotary wing shaft which is protruding under the lower washing tub shaft, the clutch spring is covered by respective two clutch gear cases at the lower washing tub shaft side and at the lower rotary wing shaft side, each clutch gear is arranged around the surface of each clutch gear case, each end of the clutch spring is fixed at each inside wall of each clutch gear case, each clutch gear engages each clutch piece or separates from each clutch piece, the clutch piece is arranged at the tip of the lever which operates by on-off voltage supply to the actuator, the lever is coupled to the brake band wound around the outer periphery of the brake drum which is arranged around the planet gear, wherein the washing operation is carried out by engaging the two clutch pieces at the upper and bottom to respective clutch gears and simultaneously fastening the brake drum, or by engaging the two clutch pieces at the upper and bottom to respective clutch gears and simultaneously loosening the brake drum, and the dewatering operation is carried out by separating the two clutch pieces at the upper and bottom from respective clutch gears and simultaneously loosening the brake drum.

13. An electric washing machine according to claim 12, wherein the operation for engaging the two clutch pieces at the upper and bottom to respective clutch gears and simultaneously fastening the brake drum is carried out by on-off operation of the voltage supply to the actuator.

14. An electric washing machine according to any one of the preceding claims, wherein said fixed mode and said free rotation mode for fixing and rotating the washing tub respectively are selectable according to contents or kinds of clothing.

15. An electric washing machine according to any one of the preceding claims, wherein rotation angle of the washing tub in free rotation mode is controlled so as to be less than a predetermined angle.

16. An electric washing machine according to claim 15, wherein the control of said washing tub is carried out by controlling on-off time of voltage supplied to the motor according to detection of rotation angle of the washing tub, or by controlling rotation angle of the motor.

17. An electric washing machine according to any one of the preceding claims, comprising: a circulating water channel which is arranged in the washing tub for circulating washing water in the washing tub by pumping up the water from a bottom part of said tub to an upper part, pumping up being operable in both the fixed mode and the free rotation mode.

18. An electric washing machine according to claim 17, comprising: a lint removing means for operating the rotary wing through a rotation angle of less than 3600 while water is additionally supplied up to a water level where circulating water is obtained by pumping up at washing or rinsing process.

19. An electric washing machine according to any one of the preceding claims, wherein the selection of the fixed mode and the free rotation mode for fixing and rotating the washing tub respectively is carried out using washing operation switch by user.

20. An electric washing machine according to any one of the preceding claims, wherein said washing tub rotates in a free rotation mode after a dewatering process is completed.

21. An electric washing machine according to any one of the preceding claims, wherein the washing tub in the free rotation mode is switched toward a reverse direction by a short time repetition.

22. An electric washing machine according to any one of the preceding claims, wherein water is supplied during an inertial rotation of said washing tub in the free rotation mode after dewatering process is completed which is carried out before rinsing.

23. An electric washing machine according to any one of the preceding claims, wherein the free rotation mode is automatically switched to the fixed mode when a cover of the washing tub is opened during operation in the free rotation mode.

24. An electric washing machine according to any one of the preceding claims, wherein a differential factor (= rotation speed of the washing tub r rotation speed of the rotary wing) is selected to be substantially less than 0.5 during the free rotation mode for rotating the washing tub freely.

25. An electric washing machine according to any one of the preceding claims, wherein the washing tub is a washing and dewatering tub, a water tub is arranged around the washing and dewatering tub, and a drain outlet is provided to drain the water out of the water tub for dewatering process.

26. An electric washing machine constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 23 of the accompanying drawings.