GB1562777A

GB1562777A - Horizontal drum laundry washing machine

Info

Publication number: GB1562777A
Application number: GB4535/77A
Authority: GB
Original assignee: Thomson-Brandt SA
Current assignee: Thomson-Brandt SA
Priority date: 1976-02-03
Filing date: 1977-02-03
Publication date: 1980-03-19
Also published as: IT1076573B; FR2340391B2; FR2340391A2; DE2704111A1; ES455526A1

Description

(54) A HORIZONTAL DRUM LAUNDRY WASHING MACHINE (71) We, THOMSON-BRANDT a French body corporation of 173, Boulevard Haussmann, 75008 Paris, France, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a laundry washing machine having a horizontal drum.

There is already a known washing machine which has a tank, a pump for draining the tank, a horizontal laundry drum, a D.C. motor to drive the laundry drum, and a programme device to control the operations carried out by the machine, and in which the washing programmes include a spin drying operation which begins at the same time as the supply of water in the tank begins to empty and which includes at least a phase 1 in which the supply of water is present in the tank and the speed of rotation of the drum increases relatively slowly from the washing speed of substantially 90rpm; a phase 2 in which a residue of the water supply is present in the tank and the speed of the drum is substantially constant and substantially 90 rpm; a phase 3 in which the tank is practically empty and the speed of the drum is progressively increased to substantially 120 rpm; and a phase 4 in which the speed of the drum increases relatively slowly to a speed of substantially 170 rpm, before a possible entry into other phases in which the speed of rotation of the drum is higher.

In such a washing machine, spin-drying takes a relatively long time.

The present invention, which seeks to overcome this disadvantage makes it possible for an improved washing machine to be produced in which the spin-drying time is reduced to a minimum and there is virtually no imbalance, no vortex of water in the drum. and no great consumption of supply current in the course of the spin drying operation.

Accordingly the present invention consists in a laundry washing machine which has a tank, a pump for draining the tank, a horizontal laundry drum, a motor to drive the laundry drum, and a programme device to control the operations carried out by the machine, and in which the washing programmes includes a spin-drying operation which begins at the same time as the supply of water in the tank begins to empty, the said spin-drying operation including at least a phase 1 in which the supply of water is present in the tank and the speed of rotation of the drum increases relatively from the washing speed to a speed of substantially S0 rpm, and a phase 2 in which a residue of the water supply is present in the tank and the speed of the drum increases relatively slowly to a speed of substantially 160 rpm, before the entry into other spin-drying phases in which the speed of rotation of the drum is higher.

In order that the invention may be better understood, an embodiment is described below with reference to the accompanying partial curve which shows, as a function of time in seconds, the speed of rotation in revolutions per minute at the end of operation of washing the laundry and during a large part of the operation of spin-drying it.

As in a known machine which is not shown, a laundry washing machine embodying the present invention has a cabinet, a tank, a pump for draining water from the tank, a horizontal laundry drum, an electric motor to drive the laundry drum, and a programme device to control the operations performed by the machine. The drive motor is an electric motor of a known kind which is able to turn at any selected speed between zero and a speed equal to or greater than 800 rpm for example. The machine is arranged to wash laundry at a speed of the order of 50 rpm.

In one of the operating programmes which will be taken as an example, this washing machine carries out a spin-drying operation on the laundry following a procedure which is indicated in broad outline by the above-mentioned representative curve.

This operation of spin-drying the laundry commences at the same time as the draining of the tank, which then contains its full supply of water of 40 litres.

At the end of the washing operation, which corresponds to section AB of the curve for drum speed, the drum is turning at 50 rpm and it is here that a phase 1 of the spin-drying operation, represented by section BC, begins. In this phase 1 of the spin-drying operation, the laundry drum, as it churns through the supply of water in the tank, rapidly increases its speed to enable it to reach 80 rpm. At a speed of 80 rpm the drum, as it rotates, does not set u a vortex of the kind which, in machines o the type which have an access opening at the top, causes an unpleasant noise when it strikes the joint which connects the tank to this access opening, nor, at this speed, is the laundry forced hard against the wall of the drum at too early a stage. In a phase 2 of the spin-drying operation, which corresponds to section CD of the speed curve, the speed of the drum rises slowly to reach a value of 160 rpm. In this phase 2 of the spin-drying operation, whose duration is approximately 60 seconds, there is a combination of a relatively gradual rise in the speed of the drum and a relatively slow decrease in the supply of water in the tank which has been going on from the beginning of spin-drying phase 1, which combination allows a major proportion of the water to b removed from the laundry and at the same time allows the laundry to be properly distributed around the drum, thus preventing an imbalance from occurring, given that the articles of laundry, which are floating in the water and in this phase are still only subject to low centrifugal force, find it easy to slide across one another. The tank has been virtually emptied of water before the end of phase 2. The total duration of phases 1 and 2 is from 60 to 90 seconds. The spindrying operation then enters a phase 3 in which the drum, having been relieved of the weight of the water extracted from the laundry, goes from its speed of 160 rpm to one of 450 rpm with a limited acceleration, which avoid a heavy current drain whilst the machine is operating. The acceleration is however still adequate to enable resonant frequency bands to be passed without any problems. Phase 3 of the spin-drying operation corresponds to section DE of the curve for drum speed. In a phase 4 of the spindrying operation, which corresponds to section EF of the speed curve, the drum turns at 450 rpm. Depending on the nature of the laundry, the final spin-drying may take place at a speed lower than 450 rpm, or at a speed between 450 rpm and 800 rpm, or at a higher speed, and may conclude, as in a known machine, with the laundry being untangled at a speed equal to or lower than 50 rpm.

The washing machine described thus has the advantage that it spin-dries the laundry properly and takes a relatively short time te do so, by virtue in particular of the phases 1 and 2 which, although of the order of 60 to 90 seconds, not only enable the laundry to be properly distributed in the drum but also enable a large amount of water to be removed from the laundry in them before the said drum completes the spin-drying operation by rotating at a speed higher than 160 rpm.

It will be appreciated that small variations are possible from the various rates of revolution given in this specific description.

WHAT WE CLAIM IS: 1. A laundry washing machine which has a tank, a pump for draining the tank, a horizontal laundry drum, a motor to drive the laundry drum, and a programme device to control the operations carried out by the machine, and in which the washing programmes include a spin-drying operation which begins at the same time as the supply of water in the tank begins to empty, the said spin-drying operation including at least a phase 1 in which the supply of water is present in the tank and the speed of rotation of the drum increases relatively rapidly from the washing speed to a speed of substantially 80 rpm, and a phase 2 in which a residue of the water supply is present in the tank and the speed of the drum increases relatively slowly to a speed of substantially 16û rpm, before the entry into other spindrying phases in which the speed of rotation of the drum is higher.

2. A machine according to claim 1, wherein the length of phases 1 and 2 of the spin-drying operation in its washing programmes is from 60 to 90 seconds.

3. A laundry washing machine having a spin-drying programme substantially as hereinbefore described with reference to the accompanying drawing.

4; A method of operating a laundry washing machine which has a tank, a pump for draining the tank, a horizontal laundry drum, a motor to drive the laundry drum, and a programme device to control the operations carried out by the machine, and in which the washing programmes include a spin-drying operation which begins at the same time as the supply of water in the tank begins to empty wherein the said spindrying operation includes at least a phase 1

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. order of 50 rpm. In one of the operating programmes which will be taken as an example, this washing machine carries out a spin-drying operation on the laundry following a procedure which is indicated in broad outline by the above-mentioned representative curve. This operation of spin-drying the laundry commences at the same time as the draining of the tank, which then contains its full supply of water of 40 litres. At the end of the washing operation, which corresponds to section AB of the curve for drum speed, the drum is turning at 50 rpm and it is here that a phase 1 of the spin-drying operation, represented by section BC, begins. In this phase 1 of the spin-drying operation, the laundry drum, as it churns through the supply of water in the tank, rapidly increases its speed to enable it to reach 80 rpm. At a speed of 80 rpm the drum, as it rotates, does not set u a vortex of the kind which, in machines o the type which have an access opening at the top, causes an unpleasant noise when it strikes the joint which connects the tank to this access opening, nor, at this speed, is the laundry forced hard against the wall of the drum at too early a stage. In a phase 2 of the spin-drying operation, which corresponds to section CD of the speed curve, the speed of the drum rises slowly to reach a value of 160 rpm. In this phase 2 of the spin-drying operation, whose duration is approximately 60 seconds, there is a combination of a relatively gradual rise in the speed of the drum and a relatively slow decrease in the supply of water in the tank which has been going on from the beginning of spin-drying phase 1, which combination allows a major proportion of the water to b removed from the laundry and at the same time allows the laundry to be properly distributed around the drum, thus preventing an imbalance from occurring, given that the articles of laundry, which are floating in the water and in this phase are still only subject to low centrifugal force, find it easy to slide across one another. The tank has been virtually emptied of water before the end of phase 2. The total duration of phases 1 and 2 is from 60 to 90 seconds. The spindrying operation then enters a phase 3 in which the drum, having been relieved of the weight of the water extracted from the laundry, goes from its speed of 160 rpm to one of 450 rpm with a limited acceleration, which avoid a heavy current drain whilst the machine is operating. The acceleration is however still adequate to enable resonant frequency bands to be passed without any problems. Phase 3 of the spin-drying operation corresponds to section DE of the curve for drum speed. In a phase 4 of the spindrying operation, which corresponds to section EF of the speed curve, the drum turns at 450 rpm. Depending on the nature of the laundry, the final spin-drying may take place at a speed lower than 450 rpm, or at a speed between 450 rpm and 800 rpm, or at a higher speed, and may conclude, as in a known machine, with the laundry being untangled at a speed equal to or lower than 50 rpm. The washing machine described thus has the advantage that it spin-dries the laundry properly and takes a relatively short time te do so, by virtue in particular of the phases 1 and 2 which, although of the order of 60 to 90 seconds, not only enable the laundry to be properly distributed in the drum but also enable a large amount of water to be removed from the laundry in them before the said drum completes the spin-drying operation by rotating at a speed higher than 160 rpm. It will be appreciated that small variations are possible from the various rates of revolution given in this specific description. WHAT WE CLAIM IS:

1. A laundry washing machine which has a tank, a pump for draining the tank, a horizontal laundry drum, a motor to drive the laundry drum, and a programme device to control the operations carried out by the machine, and in which the washing programmes include a spin-drying operation which begins at the same time as the supply of water in the tank begins to empty, the said spin-drying operation including at least a phase 1 in which the supply of water is present in the tank and the speed of rotation of the drum increases relatively rapidly from the washing speed to a speed of substantially 80 rpm, and a phase 2 in which a residue of the water supply is present in the tank and the speed of the drum increases relatively slowly to a speed of substantially 16û rpm, before the entry into other spindrying phases in which the speed of rotation of the drum is higher.

in which the supply of water is present in the tank and the speed of rotation of the drum increases relatively rapidly from the washing machine to a speed of substantially 80 rpm, and a phase 2 in which a residue of the water supply is present in the tank and the speed of the drum increases relatively slowly to a speed of substantially 160 rpm before the entry into other spin-drying phases ill which the speed of rotation of the drum is higher.

5. A method according to claim 1 wherein the length of phases 1 and 2 of the spin-drying operation in its programmes is from 60 to 90 seconds.

6. A method of operating a laundry washing machine having a spin-drying programme substantially as hereinbefore described with reference to the accompanying drawing.