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EP 0 386 724 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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27.07.1994 Bulletin 1994/30 |
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Date of filing: 07.03.1990 |
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International Patent Classification (IPC)5: D06F 39/08 |
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Washing machine
Waschmaschine
Machine à laver
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Designated Contracting States: |
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DE ES FR GB |
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Priority: |
07.03.1989 IT 6715589
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Date of publication of application: |
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12.09.1990 Bulletin 1990/37 |
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Proprietor: MERLONI ELETTRODOMESTICI S.p.A. |
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I-60044 Fabriano (AN) (IT) |
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Inventor: |
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- Agnes, Pierangelo
I-10045 Piossasco (TO) (IT)
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Representative: Dini, Roberto, Dr. Ing. |
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Merloni Elettrodomestici S.p.A
Ufficio Brevetti e Marchi
Via Pinerolo 25 10060 None (TO) 10060 None (TO) (IT) |
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References cited: :
DE-A- 2 655 556 FR-A- 1 339 811
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DE-U- 7 813 880
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention relates to a washing machine comprising a washing chamber with
a first hole on its lower side connected to a drain pump through a pipe, and with
a second hole connected to said drain pump through a pipe, and inside said washing
chamber a drum revolving around a horizontal axis.
[0002] As known, one problem washing machine manufacturers have to solve is to reduce the
waste of soap-powder, as it used to occur in the machines till a few years ago due
to the intake method of said powder. Soap-powder is taken in from the so-called "dispenser"
by means of a water jet conveying the powder into the washing chamber within a time
ranging from 90 to 120 secs.
[0003] Obviously, the major part of the soap-powder is flushed in during the initial seconds
of intake, so that initially soap-powder concentration is very high.
[0004] Said soap-powder, with is not yet dissolved, deposits mixed with water on the lowest
part of the washing chamber where there is the pipe connecting to the discharge pump,
which for hydraulic reasons should be the lowest spot of the system.
[0005] It is obvious that the pump screw and connected pipes fill up with said water soap-powder
mix, which will remain inactive during both pre-wash and wash cycles, as it is not
in contact with the laundry inside the drum.
[0006] During the last few years several systems have been suggested to obviate to such
an inconvenience causing a waste of soap-powder whereby both the washing costs and
environmental pollution increase.
[0007] As an example, German Patent Application nr. 26 55 556 describes a washing machine
where the washing chamber has a further hole connected to the discharge pump in addition
to the standard outlet hole.
[0008] Such an additional hole is located above the water level normally reached by the
water in the washing chamber; during washing cycle the alternate drum rotation causes
a water motion and a small part of water falls into such an additional hole acquiring
enough speed by gravity so as to flow back up to the washing chamber through the standard
outlet hole.
[0009] Through such a circulation it is possible to reduce the waste of soap-powder, as
a part of the powder initially accumulated in the discharge system is recirculated.
[0010] Italian Patent nr.
1 083 306 describes a washing machine with a soap-powder recovery system similar to the one
described in the German application; however, it is provided with a second hole at
a lower level than normally reached by the water in the washing chamber; according
to the patent application circulation is obtained anyway, since due to the drum motion
some differences of hydraulic pressure occur.
[0011] Said system are not very efficient though ensuring a partial recovery of the soap-powder
being wasted.
[0012] Purpose of the present invention is to indicate a washing machine with a system as
simple as the ones already known but performing to a more efficient extent for the
recovery of the greatest part of soap-powder accumulated inside the discharge pipe
system during intake.
[0013] To achieve said purpose it is the aim of the present invention to realize a washing
machine comprising a washing chamber with a first hole on its lower side connected
to a drain pump through a pipe, and with a second hole connected to said drain pump
through a pipe, and inside said washing chamber a drum revolving around a horizontal
axis, characterized in that during washing the configuration of said revolving drum
produces an effect that is similar to that of a pump propeller; that such second hole
is located preferably at a level not over the one where is located said first hole,
and that the washing chamber is configurated in such a way to have the pipe connecting
said second hole to the drain pump arranged tangentially to the drum rotation sense,
so that when the drum rotates it causes the washing fluid to enter said second hole
and said tangential pipe with enough force to cause an efficient circulation of said
fluid, which flows back into the washing chamber through said first hole.
[0014] Other purposes and advantages of the present invention are clearly detailed in the
following description and annexed drawings supplied by way of explanatory but not
limiting example, where:
- the figure is a sectional view of the washing chamber and discharge piping of a washing
machine according to the present invention.
[0015] In said figure describing the washing chamber and outlet hoses of a washing machine
according to the present invention, ref. nr. 1 refers to the washing chamber, which
may be of enamelled sheet, stainless steel or plastic material; washing chamber 1
shows number 2 a first hole connected to the drain pump 3 by a pipe, namely to an
upright pipe-socket of said pump.
[0016] Washing chamber 1 also shows a second hole referred under number 4, tangential to
the washing chamber but slightly lower than the first hole 2.
[0017] The second hole 4 is connected to the same pump 3 through a pipe 8. Pump 3 shows
a third outlet pipe-socket 6.
[0018] Washing chamber 1 contains the revolving drum 7, where the laundry to be washed is
introduced; said drum 7 has three V-shaped recesses 5, whose vertexes are directed
to the drum centre.
[0019] The special drum configuration as well as that of the washing chamber cooperate to
let the drum acting as a real and true pump propeller whose screw, in the specific
instance, is represented by the washing chamber.
[0020] During pre-wash and/or washing the drum rotates both clockwise and anti-clockwise
alternatively at a speed rate of about 60 rev/min.
[0021] With the pipe connecting the washing chamber to the pump arranged perfectly tangential
to a washing chamber wall the condition is obtained where the drum exerts a pressure
inside the pipe itself by rotating tangentially to the piping.
[0022] Thus, an efficient circulation from the washing chamber to the pump and back again
to the washing chamber is ensured, so that the soap-powder that otherwise would remain
unused is returned to the washing chamber.
[0023] Due to the washing and pre-wash times lasting long enough, it is possible for the
soap-powder to dissolve and be recovered.
[0024] The characteristics of the above washing machine are clearly shown in the above description
and annexed drawings.
[0025] Likewise the above description is also clearly showing the advantages of the washing
machine according to the present invention; as a matter of fact, both the synergy
obtained through the special drum configuration and arrangement of the second hole
as well as the tangential location of the relevant piping allow an efficient circulation,
without any cost increase, for the recovery of most part of the soap-powder accumulated
at the bottom of the machine during intake stage.
[0026] It is obvious that for the man skilled in the art many other changes are possible
to the washing machine described by way of example but without departing from the
scope of the innovating criteria inherent of the present invention.
1. Washing machine, comprising a washing chamber with a first hole on its lower side
connected to a drain pump through a pipe, and with a second hole connected to said
drain pump through a pipe, and inside said washing chamber a drum revolving around
a horizontal axis, characterized in that during washing the configuration of said
revolving drum (7) produces an effect similar to that of a pump propeller, that said
second hole (4) is located preferably at a level not over the one where is located
said first hole (2), and that the washing chamber is configurated in such a way to
have the pipe (8), connecting said second hole to the drain pump, arranged tangentially
to the drum (7) rotation sense, so that when the drum (7) rotates it causes the washing
fluid to enter said second hole (4) and said tangential pipe (8) with enough force
to cause an efficient circulation of said fluid, which flows back into the washing
chamber (1) through said first hole (2).
2. Washing machine according to claim 1, characterized in that the wall of said revolving
drum (7) has some V-shaped recesses (5) on its peripheral side, whose vertexes are
directed to the drum centre.
3. Washing machine according to claim 1, characterized in that the pipe connecting said
first hole (2) to said drain pump (3) is connected to said pump (3) through a pipe-socket
directed upwards.
4. Washing machine according to claim 1, characterized in that during washing said revolving
drum (7) is rotated in both directions alternatively, at a speed rate of about 60
rev/min.
1. Waschmaschine, bestehend aus einer Waschkammer mit einer ersten Öffnung an ihrer unteren
Seite, die an eine Abflußpumpe mit einem Schlauch angeschlossen ist, und einer zweiten
Öffnung, die an die Abflußpumpe mit einem Schlauch angeschlossen ist, und einer in
der Waschkammer sich um eine Horizontalachse drehenden Trommel,
dadurch gekennzeichnet, daß während des Waschvorganges die Konfiguration der Drehtrommel (7) eine Wirkung
ähnlich der eines Pumpenflügels erzeugt, daß die zweite Öffnung (4) vorzugsweise nicht
oberhalb der ersten Öffnung (2) angeordnet ist, und daß die Waschkammer so gestaltet
ist, daß der Schlauch (8) die zweite Öffnung mit der Abflußpumpe tangential zur Drehrichtung
der Drehtrommel (7) verlaufend verbindet, so daß, wenn die Drehtrommel (7) sich dreht,
sie bewirkt, daß Waschflüssigkeit mit genügendem Druck in die zweite Öffnung (4) und
in den tangentialen Schlauch (8) eintritt, um eine wirksame Zirkulation der Flüssigkeit
zu erreichen, die in die Waschkammer (1) durch die erste Öffnung (2) zurückfließt.
2. Waschmaschine nach Anspruch 1, dadurch gekennzeichnet, daß die Wand der Drehtrommel (7) an der peripheren Seite V-förmige Vertiefungen (5)
aufweist, deren Spitzen zum Trommelmittelpunkt zeigen.
3. Waschmaschine nach Anspruch 1, dadurch gekennzeichnet, daß der Schlauch, der die erste Öffnung (2) mit der Abflußpumpe (3) verbindet, durch
einen aufwärts gerichteten Schlauchanschluß an die Abflußpumpe (3) angeschlossen ist.
4. Waschmaschine nach Anspruch 1, dadurch gekennzeichnet, daß während des Waschvorganges die Drehtrommel (7) sich abwechselnd in beide Richtungen
mit etwa 60 U/min dreht.
1. Machine à laver, comprenant une chambre de lavage ayant un premier trou à sa face
inférieure, raccordé à une pompe d'évacuation par un tube, et un second trou relié
à la chambre de lavage, un tambour qui tourne autour d'un axe horizontal, caractérisée
en ce que, pendant le lavage, la configuration du tambour rotatif (7) donne un effet
analogue à celui d'une hélice de pompage, en ce que le second trou (4) est placé de
préférence à un niveau qui n'est pas supérieur à celui auquel se trouve le premier
trou (2), et en ce que la chambre de lavage a une configuration telle que le tube
(8) qui raccorde le second trou à la pompe d'évacuation est placé tangentiellement
au cercle de déplacement du tambour (7), si bien que, lorsque le tambour (7) tourne,
il provoque l'introduction du fluide de lavage dans le second trou (4) et le tube
tangentiel (8) avec une force suffisante pour que le fluide présente une circulation
efficace et revienne dans la chambre de lavage (1) par le premier trou (2).
2. Machine à laver selon la revendication 1, caracterisée en ce que la paroi du tambour
rotatif (7) a quelques cavités en V (5) du côté périphérique, les sommets étant dirigés
vers le centre du tambour.
3. Machine à laver selon la revendication 1, caracterisée en ce que le tube reliant le
premier trou (2) à la pompe d'évacuation (3) est raccordé à la pompe (3) par un tambour
de tube dirigé vers le haut.
4. Machine à laver selon la revendication 1, caracterisée en ce que, pendant le lavage,
le tambour rotatif (7) est entraîné en rotation dans les deux sens en alternance,
avec une vitese d'environ 60 tr/min.