FIELD OF THE INVENTION
The present invention relates to a washing machine. More particularly, the present
invention relates to a washing machine having two tub type
configuration/arrangement including a wash tub for washing clothes and a spin tub
for spin drying of the clothes.
BACKGROUND
In general, a washing machine for home use is a device which can easily remove dirt
and other foreign materials contained in the washing articles/clothes, using water and
detergents. Washing machine is generally categorized in two broad categories namely
automatic and semi-automatic type washing machines. In the automatic type washing
machine, only one tub is used for washing as well as spin drying of clothes. Whereas
in the semi-automatic type washing machine two tubs namely a wash tub and a spin
tub placed adjacent to each other are provided. The wash tub is used for washing of
the clothes and the spin tub is used for spin drying of the clothes. One such
construction of existing semi-automatic washing (100) is shown in Figure 1. This
washing machine (100) is provided with adjacently located wash tub (101) and spin
tub (102). Also illustrated is an instrument panel (103) for operating either the wash
tub or the spin tub.
In use, after washing the clothes in the wash tub, the clothes are required to be
transferred to the spin tub. With this construction of wash tub and spin tub adjacent to
each other, the said transfer of clothes is cumbersome and also it may happen that
while transferring the clothes from the wash tub to the spin tub for spinning purpose,
water may spill on the floor.
Also, the placement of tubs adjacent to each other occupies more space. Sometimes it
may be a problem for the user to place the washing machine at his home due to space
constraint.
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Therefore, it is the need of the art to provide a semi-automatic washing machine
which occupies less space than the washing machine already provided in the art and
solves or at least reduces the problem of spilling of water while transferring clothes
from wash tub to spin tub.
OBJECT OF THE INVENTION
The object of the present invention is to provide a washing machine which has a spin
tub mounted inside a wash tub.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, a washing machine is provided. The
washing machine comprises a housing, an outer tub located within the housing, an
inner tub located within the outer tub, an impeller disposed within the outer tub and
located below the inner tub, said outer tub and inner tub are being operated by a drive
mechanism. The drive mechanism comprises a first motor operatively connected to
the impeller through a first drive shaft, and a second motor operatively connected to
the inner tub through a second drive shaft.
According to another aspect, a washing machine is provided wherein the first drive
shaft is a hollow shaft and is connected with the first motor through a v-belt.
According to yet another aspect, a washing machine is provided wherein the first
motor is configured to rotate the first drive shaft and the impeller.
According to still another aspect, a washing machine is provided wherein the second
drive shaft is disposed so as to extend through the first shaft.
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According to one more aspect, a washing machine is provided wherein a safety
cylinder is disposed between the inner tub and the impeller for preventing entangling
of clothes onto the second drive shaft during its rotation.
According to another aspect, a washing machine is provided wherein the safety
cylinder is integrally mounted on the impeller.
According to yet another aspect, a washing machine is provided wherein the impeller
and the safety cylinder rotate in clockwise and anticlockwise direction in tandem.
According to still another aspect, a washing machine is provided wherein the impeller
and the safety cylinder are provided with rib structure.
According to one more aspect, a washing machine is provided, wherein a
predetermined clearance is disposed between the inner tub and the safety cylinder.
According to another aspect, a washing machine is provided wherein the inner tub is
detachable from the outer tub.
According to yet another aspect, a washing machine is provided wherein the first
drive shaft, the second drive shaft, the impeller and the inner tub are coaxial.
According to another aspect, a washing machine is provided wherein a bellow
surrounds the second drive shaft to provide flexibility in movement of the second
drive shaft.
BREIF DESCRIPTION OF DRAWINGS
Further aspects and advantages of the present invention will be readily understood
from the following detailed description with reference to the accompanying drawings.
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Reference numerals have been used to refer to identical or similar functionally similar
elements. The figures together with a detailed description below, are incorporated in
and form part of the specification, and serve to further illustrate the embodiments and
explain various principles and advantages, in accordance with the present invention
wherein:
Fig. 1 illustrates a conventionally known design of semi-automatic washing machine.
Fig. 2 illustrates a washing machine in accordance with one embodiment of the
present invention.
Fig. 3 illustrates a line diagram of the washing machine in accordance with one
embodiment of the present invention.
Fig. 4 illustrates the arrangement of the two drives in accordance with one
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a washing machine which addresses
the problems identified in the existing washing machines.
Referring now to the drawings, there is shown an illustrative embodiment of the
invention washing machine. It should be understood that the invention is susceptible
to various modifications and alternative forms; specific embodiment thereof has been
shown by way of example in the drawings and will be described in detail below. It
will be appreciated as the description proceeds that the invention may be realized in
different embodiments.
Before describing in detail embodiments it may be observed that the novelty and
inventive step that are in accordance with the present invention reside in the
construction of the washing machine, accordingly, the drawings are showing only
those specific details that are pertinent to understanding the embodiments of the
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present invention so as not to obscure the disclosure with details that will be readily
apparent to those of ordinary skill in the art having benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to
cover a non-exclusive inclusion, such that a setup, device that comprises a list of
components does not include only those components but may include other
components not expressly listed or inherent to such setup or device. In other words,
one or more elements in a system or apparatus proceeded by “comprises… a” does
not, without more constraints, preclude the existence of other elements or additional
elements in the system or apparatus.
Fig. 2 illustrates a washing machine (200) in accordance with an embodiment of the
present invention. This washing machine (200) is provided with a spin tub (202)
disposed inside a wash tub (201). Also illustrated is an instrument panel (203) for
operating either the wash tub or the spin tub. The washing machine may be optionally
provided with a transparent window to watch the wash and spin process in progress.
The term wash process herein refers to operation of an impeller or a pulsator. An
impeller or pulsator in a wash tub is moved or operated back and forth by a
mechanical force so as to cause movement of water in the wash tub. Further, as the
spin tub is disposed inside the wash tub, it is easier to transfer clothes from the wash
tub to the spin tub thereby avoiding/minimizing any spillage of water on the floor.
Fig. 3 illustrates washing machine (300) in accordance with a preferred embodiment
of the present invention. Fig. 3 clearly illustrates various aspects of the construction
of the washing machine. An inner tub or spin tub (302) is located in the middle of
outer tub or wash tub (301). The wash tub (301) and the spin tub (302) are driven by
two independent driving motors, a first motor (303) and a second motor (304). These
driving motors are mounted underneath the wash tub (301) in a base area (305). The
spin tub (302) is supported on an upper end of a spin shaft (307) which drives or
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rotates the spin tub and originates from the base area (305). The spin shaft gets its
power from the second motor (304) provided in the base area (305). A portion of the
spin shaft (307) in the wash tub (301) may be surrounded by a safety cylinder (308)
so as to prevent clothes from getting entangled onto the spin shaft while the wash or
spin process is in operation. A predetermined clearance may be provided between the
bottom surface of the spin tub (302) and upper circumference of the safety cylinder
(308) so as to avoid any contact between the two while the spin tub (302) rotates at
high speed during spin operation. In one embodiment, the range of this clearance may
vary between 5-50 mm while in another embodiment the range may vary between 5-
30 mm. Further, to drain water filled in the safety cylinder, the safety cylinder may
contain holes.
The safety cylinder (308) forms an integral part of the impeller (309) or the pulsator.
The impeller (309) is mounted above the inner floor of the wash tub (301) for
generating a turbulent current in the water contained in the wash tub and for applying
a water power to the clothes being washed thereof. During wash process, the impeller
(309) rotates clockwise and anti-clockwise alternatively to form water current. The
impeller (309) is driven by an impeller shaft (306) which is a hollow shaft and is
operatively connected to a first motor (303) via a pulley. The spin shaft (307) is
disposed so as to extend through the hollow of the impeller shaft (306). During spin
process, the spin tub (302) rotates at high speed while the impeller (309) remains
stationary. Further, the spin tub (302), the safety cylinder (308) and the impeller (309)
may be provided with ribs on the surface which is in contact with water in the wash
tub (301). These ribs help in providing mechanical friction or additional turbulence in
the water current thus aiding in washing of the clothes.
In one embodiment of the present invention, the spin tub (302) can be detached to
increase the capacity of the wash tub (301). In such a case, the safety cylinder (308)
may be provided with a cap to cover it from the top side.
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Fig. 4 illustrates the arrangement of the two shafts for the spin tub (402) and the
impeller (409) in accordance with an embodiment of the present invention. The figure
shows a drive system along with the arrangement of the first motor (403) and the
second motor (404) in the base area (405) of the washing machine (400). The second
motor (404) is mounted on a bracket (410) which is supported by four suspension
members (411). The shaft (407) for the spin tub (402) is connected to the second
motor (404) with the help of a coupling (412) so as to transfer the drive from the
second motor (404) to the spin tub (402). The other end of this shaft (407) is
connected to the base of the spin tub (402).
The first motor (403) is mounted rigidly on the base of the base area (405) of the
washing machine (400). A pulley (413) which is mounted on a first motor shaft is
driven by the motor with the help of a v-belt. The v-belt transfers the motion from the
first motor (403) to the impeller (409) via the impeller shaft (406) for the impeller.
The impeller shaft (406) for the impeller and the spin shaft for the spin tub are
arranged such that the impeller shaft (406) for the impeller surrounds the spin shaft
for the spin tub. The arrows in the figure show the direction of transmission of motion
for the spin and the wash processes.
Further the washing machine is provided with a bellow (414) surrounding the spin
shaft (407). The bellow provides flexibility in movement of the spin shaft ( 407)
during imbalance. In addition to this, various seals at various locations are provided
in this arrangement to give a sealing effect. One such seal is provided between the
spin shaft and the bellow gap. Further, a rectangular seal is provided in the gap
between the bellow and the impeller shaft.
In the foregoing description, the wash tub may be interchangeably used by the term
outer tub, the spin tub may be interchangeably used by the term inner tub, the
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impeller shaft may be interchangeably used by the term first shaft or first drive shaft
and the spin shaft may be interchangeably used by the term second shaft or second
drive shaft.
While the invention has been described with reference to a preferred embodiment, it
is apparent that variations and modifications will occur without departing the theme
of the invention. It is therefore contemplated that the present invention covers any and
all modifications, variations or equivalents that fall within the scope of the basic
underlying principles disclosed above and claimed therein.

WE CLAIM:
1. A washing machine, comprising:
a housing (300);
an outer tub (301) located within the housing;
an inner tub (302) located within the outer tub;
an impeller (309) disposed within the outer tub (301) and located below the
inner tub (302);
said outer tub and inner tub are being operated by a drive mechanism, said
drive mechanism comprising:
a first motor (303) operatively connected to the impeller (309) through a first
drive shaft (306); and
a second motor (304) operatively connected to the inner tub (302) through a
second drive shaft (307).
2. The washing machine as claimed in claim 1, wherein the first drive shaft (306) is a
hollow shaft and is connected with the first motor (303) through a v-belt.
3. The washing machine as claimed in claim 1, wherein the first motor (303) is
configured to rotate the first drive shaft (306) and the impeller (309).
4. The washing machine as claimed in claim 1, wherein the second drive shaft (307) is
disposed so as to extend through the hollow of the first shaft (306).
5. The washing machine as claimed in claim 1, wherein a safety cylinder (308) is
disposed between the inner tub (302) and the impeller (309) for preventing entangling of
clothes onto the second drive shaft (307) during its rotation.
6. The washing machine as claimed in claim 1, wherein the safety cylinder (308) is
integrally mounted on the impeller (309).
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7. The washing machine as claimed in claim 1, wherein the impeller (309) and the
safety cylinder (308) rotate in clockwise and anticlockwise direction in tandem.
8. The washing machine as claimed in claim 1, wherein the impeller (309) and the
safety cylinder (308) are provided with rib structure.
9. The washing machine as claimed in claim 1, wherein a predetermined clearance is
disposed between the inner tub (302) and the safety cylinder (308).
10. The washing machine as claimed in claim 1, wherein the inner tub (302) is
detachable from the outer tub (301).
11. The washing machine as claimed in claim 1, wherein the first drive shaft (306), the
second drive shaft (307), the impeller (309) and the inner tub (302) are coaxial.
12. The washing machine as claimed in claim 1, wherein a bellow surrounds the second
drive shaft (307) to provide flexibility in movement of the second drive shaft ( 307).