WASHING MACHINE WITH PUMPING DAMPER FOR AUTOMATIC BALANCING

LAVEUSE A REGISTRE DE POMPAGE POUR EQUILIBRAGE AUTOMATIQUE

English Abstract

An improved washing machine includes a tub with a rotatable drum mounted therein, in either a horizontal or vertical orientation. An open balance ring is mounted on the drum. The tub is supported by a damper which pumps fluid to the balance ring to counter balance unbalanced loads in the drum during dynamic operation of the machine.

French Abstract

Machine à laver améliorée comprenant une cuve avec un tambour rotatif installé à l'intérieur de manière soit horizontale ou verticale. Un anneau d'équilibre ouvert est installé sur le tambour. La cuve fonctionne avec un dispositif à absorption qui pompe le liquide jusqu'à l'anneau d'équilibre pour équilibrer les charges dans le tambour pendant le fonctionnement dynamique de la machine.

Claims

What is claimed is:
1. A washing machine, comprising:
a cabinet;
a tub mounted in the cabinet;
a damper to mount the tub in the cabinet;
a drum rotatably mounted in the tub;
a balance ring on the drum;
a fluid line extending from the damper; and
the damper being adapted to pump fluid through the fluid line and into the
balance ring to
counter-balance an unbalanced load in the drum.
2. The washing machine of claim 1 wherein the balance ring is open.
3. The washing machine of claim 1 wherein the damper is a piston and cylinder
assembly.
4. The washing machine of claim 1 further comprising a fluid source
operatively
connected to the fluid line.
5. The washing machine of claim 1 wherein the fluid line includes a one-way
valve to
control fluid flow through the line.
6. The washing machine of claim 1 wherein the balance ring extends 360°
around the
drum.
7. The washing machine of claim 6 wherein the balance ring has internal walls
to
define a plurality of compartments.
8. The washing machine of claim 6 wherein the balance ring includes an opening
for
receiving fluid from the fluid line.
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9. The washing machine of claim 8 wherein the opening is a slot extending
360°
around the balance ring.
10. The washing machine of claim 9 wherein the slot is on an inner peripheral
wall of
the balance ring.
11. The washing machine of claim 1 wherein the fluid line terminates in a
spray nozzle
adjacent the balance ring.
12. A method of automatically balancing an unbalanced load in a washing
machine, the
washing machine having a drum rotatably mounted in a tub supported by dampers
within a
cabinet, and a balance ring on the drum, the method comprising:
pumping fluid from one of the dampers to the balance ring when the load is
unbalanced.
13. The method of claim 12 wherein the pumping is during a dynamic cycle of
the
washing machine.
14. The method of claim 12 wherein the pumping is during a spin cycle of the
drum.
15. The method of claim 12 further comprising spraying the fluid into the
balance ring.
16. The method of claim 12 further comprising controlling fluid flow between
the one
damper and the balance ring with a one-way valve.
17. An improved washing machine having a tub with a rotatable drum therein,
and with
an open balance ring on the drum, the improvement comprising:
a pumping damper connected to the tub to pump fluid to the balance ring to
counter-
balance unbalanced loads in the drum.
18. The improved washing machine of claim 17 wherein the damper includes a
cylinder
and piston assembly.
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19. The improved washing machine of claim 17 further comprising a fluid line
extending from the damper to the balance ring.
20. The improved washing machine of claim 17 wherein the fluid line includes a
spray
nozzle for spraying fluid into the balance ring.
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Description

CA 02539090 2006-03-09
TITLE: WASHING MACHINE WITH PUMPING DAMPER FOR AUTOMATIC
BALANCING
BACKGROUND OF THE INVENTION
Clothes washing machines commonly are provided with a fluid ring to correct or
counter balance unbalanced loads during the spin operations. The fluid rings
are normally
mounted at the top edge of a vertical axis drum or the front edge of a
horizontal axis drum.
Balance rings are also known to have been provided along the side wall of a
vertical axis
drum and the rear wall of a horizontal axis drum.
Such fluid balance rings are effective at high rotational speeds to counter
balance
the unbalanced loads resulting from objects in the drum being unevenly
distributed or off-
center. An example of such a situation is a load of towels positioned along
one side of the
rotating washing machine drum, which creates an unbalance. Such an unbalanced
condition causes deflections in the rotating drum. The deflection of the
unbalanced drum
increases as the rotational speed of the drum increases, up to a critical
speed, after which
the deflections are minimized by the function of the fluid balance ring. The
critical
rotational speed varies from assembly to assembly, depending on the structure,
mass, and
geometry of the rotating assembly and its contents. The fluid within the
balance ring
counteracts the unbalanced load in the drum when the drum is rotating at high
speeds.
Washing machine suspensions typically have a very robust design to allow the
dynamic system to carry large unbalances to a water extraction speed. It is
desirable to
limit the displacement of the dynamic assembly. Prior art efforts to limit the
displacement
include tumbling of the laundry to redistribute the load, use of a sealed
dynamic fluid
balance ring, use of large concentric rings to lower the critical frequency of
the dynamic
assembly, and dynamic balancing by adding fluid to the appropriate sections of
an open
balance ring. Closed or sealed balance rings add weight to the washing
machine, which is
unnecessary until there is an unbalanced load. Also, a closed balance ring has
a fixed
weight, which may be too much or too little. Prior art open balance rings
typically include
sensors to detect when the unbalanced condition is corrected or overcome so
that the drum
can be ramped up to full rotation speed.
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CA 02539090 2006-03-09
Accordingly, a primary objective of the present invention is the provision of
an
improved washing machine having a pumping damper to automatically counter
balance an
unbalanced load in the rotating drum.
Another objective of the present invention is the provision of a washing
machine
having an open balance ring for receiving a balancing fluid when there is an
unbalanced
load in the drum.
A further objective of the present invention is the provision of a washing
machine
having an open balance ring without sensors.
Still another objective of the present invention is the provision of a method
of
automatically balancing an unbalanced load in a washing machine.
Yet another objective of the present invention is the provision of a method
for
pumping fluid from a tub damper to a balance ring when there is an unbalanced
load in the
drum.
A further objective of the present invention is the provision of a washing
machine
with a balance ring that quickly and effectively adjusts to balance loads in
the washing
machine drum.
These and other objectives become apparent from the following description of
the
invention.
SUMMARY OF THE INVENTION
The washing machine comprises a cabinet and tub mounted within the cabinet.
The
tub is supported by a plurality of dampers, with a drum rotatably mounted
within the tub.
The drum includes an open balance ring. A fluid line extends from a damper to
a spray
nozzle adjacent the balance ring. The dampers are adapted to pump fluid to the
balance
ring to counter balance an unbalanced load in the drum.
In the method of the present invention, an unbalanced load in the washing
machine
is automatically balanced by a pumping damper which pumps fluid from the
damper to the
balance ring when the load is unbalanced during a dynamic cycle of the washing
machine.
Fluid is sprayed into the open balance ring during the dynamic cycle, and is
drained from
the balance ring when the cycle is completed.
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CA 02539090 2006-03-09
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side schematic view of the automatic balancing system of the
present
invention, as used on a vertical axis washing machine, with the rotating drum
being in a
balanced state.
Figure 2 is a view similar to Figure 1 showing the drum in an unbalanced
state.
Figure 3 is an enlarged perspective view of the washing machine drum, with the
spray nozzle and open balance ring of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A washing machine is generally designated in the drawings by the reference
numeral 10. The washing machine 10 includes a tub 12 with a drum 14 rotatably
mounted
therein. For clarity, the motor and drive shaft for the drum 14 are not shown
in the
drawings. The upper end of the drum 14 includes an open balance ring 16. The
balance
ring 16 extends around the perimeter of the drum 14 and includes an internal
annular slot
18. The balance ring 16 includes internal walls so as to define compartments
therein. At
least one drain opening (not shown) is provided in the ring 16.
The tub 12 is supported by a plurality of dampers 20. Preferably, each damper
20 is
comprised of a piston 22 and a cylinder 24 which form an assembly extending
between the
tub and the base of the washing machine 10. The number of dampers depend on
the
machine. Vertical axis washers often have four dampers spaced substantially
equally about
the tub 12, while horizontal washers may have only two dampers to support the
tub.
One of the dampers 20 includes a fluid line 26 extending from the cylinder 24
to a
position adjacent the balance ring 16. The fluid line 26 terminates in a spray
nozzle 28
mounted in a fixed position, such as on the tub 12, and directed so as to
spray fluid from
the cylinder 24 into the slot 18 of the balance ring, as described below. A
fluid supply tank
or reservoir 30 is operatively connected to the fluid line 26 so as to
replenish the fluid in
the cylinder 24. The reservoir 30 is replenished with fluid from the tub 12.
One way
valves 32 are provided in the fluid line 26 to prevent backflow of fluid.
In operation, when there is a balanced load in the drum 14, the dampers 20 are
balanced and the balance ring 16 is empty of fluid. The balance state of the
washing
machine 10 is shown in Figure 1. When an unbalanced condition exists in the
drum 14, the
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CA 02539090 2013-01-09
tub and drum 14 tilt to the over-loaded side, as shown in Figure 2. As the
drum rotates, the
heavy tilted side causes the damper 20 to compress and thereby pump fluid
through the
fluid line 26 and out the nozzle 28 into the slot 18 of the balance ring 16
opposite the
compressed damper 20. As the drum 14 rotates, such as during a spin cycle, the
damper 20
pumps the fluid in a pulsating manner, drawing fluid from the reservoir 30 so
as to be
sprayed into the balance ring segment opposite the unbalanced load.
As the drum 14 becomes more balanced through the fluid in the balance ring 16,
the
displacement of the dynamic system will no longer be of sufficient magnitude
to cause the
damper 20 to spray fluid into the balance ring 16. When the spin cycle ends,
the drum 14
will coast to a stop and all the fluid in the balance ring 16 will drain,
leaving the system
ready for the next run.
While the drawings show the pumping dampers 20 utilized on a vertical axis
washing machine, it is understood that similar dampers may be utilized on a
horizontal axis
washing machine, which will operate in a similar manner as described above so
as to pump
fluid from the cylinder 24 to a balance ring when the drum is in a unbalanced
dynamic
state.
The scope of the claims should not be limited by the preferred embodiments set
forth in the description, but should be given the broadest interpretation
consistent with
the description as a whole.
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Representative Drawing