EP0496708B1

EP0496708B1 - Improved delivering-dispensing assembly for washing machines

Info

Publication number: EP0496708B1
Application number: EP92830015A
Authority: EP
Inventors: Silvano C/O Candy S.P.A. Fumagalli
Original assignee: Candy SpA
Current assignee: Candy SpA
Priority date: 1991-01-22
Filing date: 1992-01-17
Publication date: 1997-03-26
Anticipated expiration: 2012-01-17
Also published as: IT221565Z2; EP0496708A1; ITMI910043U1; DE69218473D1; DE69218473T2; ITMI910043V0

Description

BACKGROUND OF THE INVENTION

The present invention relates to a washing machine having an improved delivering-dispensing assembly.
In previous Italian Patent Applications in the name of the same Applicant, i.e. the Italian
Patent Applications No. 19716 A/87, 19564 A/88 21335 A/88 and 21576 B/90, there are illustrated improvements to washing machines and, in particular, to the drawer vessel or cup supplying to the washing machine the water and detergents for performing some washing cycles.
More specifically, in the Italian Patent Application No. 21576 B/90 (DE-A-4124376, published on 6.2.92) there is disclosed a specifically designed cup, including five compartments, which cup has been specifically designed for performing a washing start step, therein, as the washing water is supplied, there is also supplied an amount of detergent corresponding to about one third of the full detergent amount and, successively, from an over-washing compartment there is supplied the remaining portion of detergent, as the washing water has achieved a set temperature.
Thus, a more efficient washing is obtained, since a portion of the detergent is supplied into water which has already achieved a given temperature.

SUMMARY OF THE INVENTION

The document DE-B-1228220 discloses a washing machine into which is introduced a supply of an amount of water having the full close of detergent into a first amount of water having a preset temperature. On this document has been formulated the preamble of the main Claim.
The aim of the present invention is to further improve the washing efficiency of a washing machine, starting from the basic idea that this washing efficiency is directly proportional to the amount of detergent which is post-added as the washing water has obtained a desired or set temperature.
Accordingly, it is provided a washing machine having a delivering-dispensing assembly which allows to better exploit the detergent, both by reducing the loss deriving from that portion of detergent which in actual practice is not dissolved in the cold washing water, and by increasing the efficiency of said detergent, which is caused to be dissolved in water which has already been brought to a set temperature.
Moreover, a further object of the present invention is to provide a washing machine having a delivering-dispending assembly which is adapted to efficiently control all of the washing steps and, moreover, which can be easily fitted to the properties of several washing products like those which are conventionally used in washing machines.
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a washing machine, according to the main Claim.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will become more apparent from the following detailed disclosure of a washing machine having an improved delivering-dispensing assembly, according to the present invention, which is illustrated, by way of an indicative but not limitative example, in the accompanying drawing, where:

Figure 1 is a schematic view illustrating the drawer vessel according to the present invention;
Figure 2 is a schematic view showing the level of the water in the washing tub of the washing machine, after having introduced thereinto the first amount of water and after the introduction of the second amount of water; and
Figure 3 is a diagram showing the increasing of the so-called white point of the washed products, with respect to the variation of the rated amount of the washing detergent introduced into water brought to a preset temperature.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the figures of the accompanying drawing, the washing machine having an improved construction delivering-dispensing assembly according to the present invention comprises a drawer vessel, generally indicated at the reference number 1, which is provided with five compartments, respectively indicated at 2, 3, 4, 5 and 6.
Above the drawer vessel 1 there are provided water supplying means, for introducing into the washing machine the washing water, which water supply means have been generally indicated at the reference number 10.
More specifically, the compartment 2 of the drawer vessel is a pre-washing compartment, which allows the user to perform a conventional type of prewashing, by an automatic programmed pre-washing step.
In this case, the possible remaining cleaning capability of the pre-washing can be exploited in the subsequent step; the pre-washing can be of an autonomous type, of a delayed switch-on type, or it can be fully omitted, with a start of the washing cycle in a subsequent step.
Adjoining the pre-washing compartment 2 there is provided an intermediate loading compartment 3, which is provided for introducing into the washing tub of the washing machine a first amount of water so as to achieve a minimum level indicated at 1 in Figure 2; this water is provided for softening the linen, with a quick heating of the water itself.
There is moreover provided an additional compartment 4, thereinto there is introduced a second amount of water, so as to reach the over-washing level L and thereinto there is further added, as it will be disclosed in a more detailed way hereinafter, the full dose of detergent.
The compartment 5 is the compartment provided for performing the conventional introducing of the bleaching material, whereas the compartment 6 is provided for supplying possible additives such as softening substances and the like.
From performed tests it has been found that by introducing a first amount of water through the intermediate cycle compartment 3, and by bringing this water to a preset temperature, a remarkable increase of the washing efficiency is obtained, since it is obtained a great reduction of the detergent loss which, by settling, practically is not dissolved, as well as being obtained a better performance of some components of the detergent, in particular the high temperature detergent components, such as the sodium perborates and some types of sequestering agents and soaps.
As stated, during the intermediate loading step, exclusively water is introduced or supplied, that is water devoid of any detergent, with the exception of an optional addition of softening substances, specifically provided for improving the properties of the water which must be heated to provide the washing bath.
It is also possible, through the mentioned intermediate loading compartment, to introduce detergent, by loading doses of liquids devoid of any oxidizing substances and by loading, subsequently, the remaining portion of the detergent, with oxidizing substances, into the bath brought to the preset temperature.
The over-washing step, which is performed by supplying the second amount of water through the additional compartment, provides for the use of the full loaded detergent dose, with the water bath brought to the preset temperature.
This system reduces, and in actual practice overcomes,the settling loss of the detergent and the so-called chemical loss, related to a lack of oxygen development, by the oxidizing substances, at the start of each cycle and in all of the cycles performed at low temperature.
In fact, the sodium perborate provides its full oxidizing action at temperatures greater than 60°C, which are not present in the first portion of the washing cycles.
The addition of the detergent to the bath water which has been already brought to an optimal temperature, favours a quick dissolving of the perborate, expecially for the washing cycle performed at 90°C.
By using a drawer vessel including five compartments, the user has the possibility of performing a conventional washing cycle, which comprises pre-washing, washing, bleaching steps, as well as an additive addition step.
Simultaneously, there are partially solved the mechanical loss and detergent settling problems, in addition to that of the chemical loss of the characteristic properties of said detergent.
To the foregoing it is to be added that it is moreover possible to set intermediate washing programs, since the achievement of the water levels in the washing tub can be detected by electrically controlled pressure switches, as well as by switches controlling the softening minimum level, the normal level with remotion of the detergent, the over washing level, as well as with timed loading for removing the dose in the over-washing step; moreover, the subject system is compatible with the variable temperature controls, as well as with the thermo-stop or fixed controls.
From the above disclosure it should be apparent that the invention fully achieves the intended aim and objects.
In particular, is pointed out that by supplying water in two distinct steps, that is with a starting minimum water loading, for softening the linen, and a second step, by supplying the full dose of detergent, with the washing bath already brought to a preset temperature, it is possible to better exploit the characteristics and doses of detergent, thereby providing better washing results, together with a reduction of the detergent consume.
Moreover, the supplying of a minimum level of water inside the washing tub, allows to quickly heat said water, with a consequent reduction of the electrical power consume.
Finally, the disclosed construction affords the possibility of using softening or sweetening products exclusively for the amount of water which is actually necessary for the washing operation, and, moreover, it is possible to use either liquid or powder detergents, as well as detergents strengthened by oxidizing or calcium removing substances.

Claims

A washing machine, including a washing tud and a delivering-dispensing assembly comprising a drawer vessel (1), characterized in that said drawer vessel is divided into five compartments (2,3,4,5,6), on the top of which are arranged water supply means (10) for supplying washing water, said compartments comprising an intermediate loading compartment (3), for introducing into the washing tub a first amount of water, and an additional compartment (4) for introducing into said washing tub a second amount of water and the full dose of a washing detergent, the supplying of said second amount of water and full dose of detergent being performed after the first amount of water in the washing tub has reached a preset temperature.
A washing machine according to Claim 1, characterized in that the first amount of water corresponds to a minimum level of water in the tub of the washing machine, provided for softening the linen to be washed.
A washing machine according to one or more of the preceding claims, characterized in that said assembly allows sweetening products to be introduced into the first amount of water.
A washing machine according to one or more of the preceding claims, characterized in that said assembly is adapted to allow conventional washing steps to be performed, such as pre-washing, washing, bleaching and addition of additives.