GB2038372A

GB2038372A - Clothes Washing Machine with Improved Discharge Device

Info

Publication number: GB2038372A
Application number: GB7942749A
Authority: GB
Original assignee: Industrie Zanussi SpA
Current assignee: Industrie Zanussi SpA
Priority date: 1978-12-20
Filing date: 1979-12-10
Publication date: 1980-07-23
Also published as: FR2444743A1; GB2038372B; DE2947941C2; FR2444743B1; ES487149A1; DE2947941A1; IT1108928B; IT7845736A0

Abstract

A clothes washing machine has a water discharge device 8 for discharging water and comprising a discharge pump 9 upstream of which there is fixed a hollow housing 24 connected to an intake conduit (7), Figure 2 (not shown), from the bottom of the tub 10, to a recirculation conduit 21, and to a discharge conduit 20 of the machine, the housing 24 containing an annular member 25 provided with an axial extension 28 of circular sector form extending on the opposite side with respect to the pump 9, and a transfer member 26 of generally cylindrical shape which is provided with openings 34, 35, 27 associated with the various conduit connections, first and second seals 30, 39 between the annular member 25 and the housing 24 and between the transfer member 26 and housing 24 and a frontal closure member 41 engageable with the housing 24 and said transfer member 26 and being capable of assuming in a closing condition a first position in which said first seal 30 is clamped and a following position in which said second seal 39 is clamped. The pump 9 is provided with a rotor 50 having helicoidal blades 51 and a "pointed arch" central boss 52. <IMAGE>

Description

SPECIFICATION Clothes Washing Machine with Improved Discharge Device The invention relates to a clothes washing machine.

Clothes washing machines are known, which are provided with a discharge device comprising a pump whose intake side is connected to the bottom of the washing tub by way of a flexible tube and a filtering unit and whose discharge side is connected to the discharge conduit of the machine.

In practice however it has been found that, in various washing cycles, the filtering member tends to retain not only any foreign bodies which may be present, but also any threads which may be present, for example those which are produced when cotton or woollen items are washed.

In such a case, the filtering member is progressively blocked so that it becomes difficult to discharge the water, and in consequence it is necessary to clean the filtering member frequently.

In order to overcome such disadvantages, it has been proposed that the filtering member may be eliminated and that the discharge unit and the associated pump may be so constructed that they can discharge directly to the exterior any foreign bodies and threads which may occur.

For this purpose, a self-cleaning discharge unit is known, which is provided with an intake aperture and a discharge aperture, which are connected to an agitation chamber provided within the discharge unit and in which the rotor of the discharge pump is housed. The rotor is provided with blades which are of a particular hollow profile, and is mounted on the bottom of the agitation chamber in such a way that the forwardly projecting portions of the rotor and the central boss of the rotor are aligned with the edge of the outlet opening of the discharge aperture configuration. However, practice has shown that an inactive region is formed at the position of the boss of the rotor. In this region threads tend to be deposited, forming a lump on the actual boss, whereby the agitation chamber is progressively blocked.

Another solution is also known, wherein there is provided a discharge unit of the decantation type, also comprising an intake aperture and a discharge aperture which are respectively connected to an intake chamber and a discharge chamber provided within the discharge unit and which are separated from each other by a dividing wall. The intake chamber can be sealingly closed forwardly by a cover comprising two members, while the discharge chamber contains the rotor of the discharge pump. The above-mentioned dividing wall is provided with a central aperture and is held in position by means of bolts which are fixed to a member of the cover, which is sealed against the internal cover means of the discharge unit by the pressure applied to the second member of the cover.In addition, the boss of the rotor partly penetrates into the opening provided in the dividing wall, thereby defining a limited flow aperture for the water to flow towards the discharge. With this arrangement, in the discharge phase, any foreign bodies and threads which may be present cannot pass into the discharge chamber, because they are retained either by the particular configuration of the central opening in the dividing wall or by the boss of the rotor which partly engages into the opening, and are therefore collected on the bottom of the intake chamber.

Thus, in order to remove the foreign bodies and threads, it is sufficient to release the members of the cover from the body of the discharge unit in order to have direct access to the intake chamber.

However, this construction suffers from the disadvantage that, in the course of various washes, the threads may progressively accumulate around the above-mentioned bolts and may thus block the intake chamber, so that discharge of the water is consequently difficult. In this case also therefore, in order to ensure efficient discharge of water, it is necessary to have frequent access to the interior of the discharge unit in order to remove therefrom the foreign bodies and threads which have accumulated in this way.

A further disadvantage which is not overcome by the above-mentioned discharge units is that of excessive consumption of detergent, inasmuch as a part of the detergent introduced into the tub (which can be as much as 20 to 50%) collects in the flexible conduit which connects to the tub and in the discharge unit and consequently, since this detergent cannot be recirculated in the tub of the machine due to the absence of convection movements, it remains unused.

In order to eliminate this further disadvantage, various systems have been proposed for making use of all the detergent which is put into the tub of the washing machine.

A detergent recovery system has been produced by means of a conduit for recirculating the water, which is connected at one end to the discharge unit of the machine and which opens at the other end into the tub of the machine.

Such a recirculating conduit is known for example from Italian patent applications Nos.

4571 5/A-77 and 4571 7/A-77 which were filed on 13th May 1977 by the present applicants, wherein the above-mentioned recirculating conduit opens into the tub of the clothes washing machine respectively below the minimum level to which the tub is filled with water, and at a level which is between the maximum static filling level and the minimum dynamic level which can be reached by the water when the drum rotates at the washing speed.

As fully described in the above-indicated applications, water mixed with the detergent circulates by means of the recirculating conduit, such circulation being facilitated by the presence of a suitable deflector plate which is fixed to the inside surface of the tub, in association with the aperture in the tub connecting to the recirculation conduit. However, a part of the detergent introduced into the tub, by passing through the bottom opening thereof, passes into the flexible conduit connecting to the discharge unit, and is deposited in the folds in the conduit itself and is difficult to remove, even if the water is at a high temperature and if the above described recirculation takes place.

It shouJd be also be noted that when the detergent recovery operation is performed, the discharge pump is taken out of operation and the water mixed with the detergent is circulated through the discharge unit. This involves some pressure or charge losses within the recirculation system, with the consequence of reducing the amount of detergent recovered.

According to the present invention, there is provided a clothes washing machine having: a washing tub; a drum which is rotatable in the tub; and a discharge device for discharging water from the machine, the discharge device comprising a discharge pump upstream of which there is fixed a hollow housing provided with connecting means for connection to an intake conduit from the bottom of the tub, to a recirculation conduit for recirculating the water from tub and to a discharge conduit of the machine, wherein that housed within said housing are an annular member provided with an axial extension of circular sector form extending on the opposite side with respect to the pump, and a transfer member of generally cylindrical shape which is provided with openings associated with said connecting means, first sealing means being provided between said annular member and a projection in the interior of said housing and second sealing means being provided between said transfer member and said housing, a frontal closure member being engageable with said housing and said transfer member and being capable of assuming in a closing condition a first position in which said first sealing means is clamped and a following position in which said second sealing means is clamped.

The features and advantages of the present invention will be better apparent from the following description by way of non-limiting example with reference to the accompanying drawings in which: Figure 1 shows a partly sectional side view of part of one embodiment of the present invention; and Figure 2 shows a front view of the device of Figure 1 partly in section taken along line A-A in Figure 1.

Referring to the drawings, reference numeral 5 denotes the washing tub of a domestic clothes washing machine which apart from the portions shown in the drawings may be of conventional type. The tub 5 is supported in the frame of the machine by a per se known damping system (not shown) and the drum 6 rotates within the tub about a horizontal axis.

The discharge device of the machine essentially comprises a flexible conduit 7 which is in the form of a rubber corrugated tube, a discharge unit 8 and an electric discharge pump 9.

As can be seen from Figure 2, the flexible conduit 7 is connected between the bottom opening 10 of the tub 5 (by means of a ring 1 1 or similar means) and the intake connecting means 12 of the discharge unit 8 (by means of a ring 13 or similar means).

In a position below the bottom opening 10 of the tub 5, the flexible conduit is so shaped as to form a collecting vessel 14 which is provided internally with a lower collecting surface 15 and an upper lip portion 1 6. Towards the mouth of the conduit 7, the surface 15 terminates in a raised edge portion 17. The lip 16 projects into the tub 5 and acts as a deflector plate as will be described hereinafter. The discharge unit 8 comprises an internally hollow generally cylindrical body or housing 18 which is provided with an intake connecting means (connected to the tub bottom as described hereinbefore), a recirculation connecting means 19 and a discharge connecting means 20 connected to the discharge conduit of the machine (not shown).The recirculation connecting means 19 is connected by way of a further flexible conduit 21 acting as a recirculation conduit to an aperture 22 which is provided through the lower side wall of the tub 5.

For the purposes of the present invention, the recirculation conduit serves to provide for recovery of the detergent which is accumulated in the discharge device of the machine, and is exactly similar to those devices described in patent applications Nos. 4571 5/A-77 and 4571 7/A-77 filed on 13th May 1977 by the present applicants, to which reference should be made in order to ascertain the mode of operation of the detergent recovery system of which it is part.

Reference will now be made to Figure 1 which shows the manner in which the discharge unit 8 is associated with the lower frontpart of the casing 23 of the machine, in such a way as to be accessible from the exterior.

In the embodiment illustrated, for reasons of space and accessibility, the discharge unit is disposed in an inclined position with respect to the horizontal plane in which the clothes washing machine stands on the floor.

Obviously, the discharge unit may also be disposed at different angles of inclination with respect to the horizontal plane referred to above, without thereby departing from the scope of the present invention, provided that the rotor of the pump is always visible from the front part of the machine after opening the discharge unit 8.

The body 18 of the discharge unit 8 is fixed in the front part of the casing 23 of the washing machine and is accessible from the exterior by way of a removable closure member 24. The body 18 has an internal chamber which is arranged to receive respectively a first member 25 of annular shape and a second member 26 of generally cylindrical shape.

The first member 25 has a central through aperture 27 and an axial extension 28 of circular sector shape, and also a series of outside circular sectors 29, and is provided with an external sealing means 30 which is arranged to butt against a circular projection 31 provided within the body 18.

In order to permit the sealing means to operate correctly as will be described hereinafter, a metal reinforcing ring 32 is provided between the sealing means and the circular sectors 29.

At its end which is introduced into the body 18, the second member 26 has a discontinuous circular recess 33 in its internal surface, which is arranged to come into clipping engagement with the corresponding series of circular sectors 29 of the first member 25, such engagement occurring when the second member 26 is completely introduced into the body 18.

In order to ensure accurate assembly, the second member 26 is guided within the body 18 by means of a rib-and-groove system (not shown) which permits insertion thereof in its predetermined position.

The second member 26 is also provided with two through apertures 34 and 35 which are provided in its body 36 in such a way that, when it is completely introduced into the body 18, in the position of engagement with the first member 25 as referred to hereinbefore, the first through aperture 34 coincides with the intake connecting means 12 of the discharge unit 8 and the second through aperture 35 coincides with the recirculation connecting means 19 of the discharge unit (Figure 2).

Associated with the closed end portion 37 of the second member 26, on the exterior thereof, is a projecting collar 38 on which there is fitted a sealing means 39 which acts in a radial direction and which is arranged to prevent loss of water to the outside of the discharge unit 8, and also a plurality of elastic projecting sectors 40.

The front end 60 of the body 18 is screwthreaded on its exterior so as to permit a screw-threaded circular closure member 41 to be screwed on to and unscrewed from the body 18.

The closure member 41 is provided with a circular projection 42 which is arranged to abut against the sealing means 39, by way of at least one interposed washer member 43 in order to reduce wear. The closure member 41 is also provided with a plurality of projecting elastic sectors 44 whose terminal edge 45 is arranged to engage with the above mentioned sectors 40 on the end portion 37.

The arrangement of the sectors 40 and 44 is such as to permit them to come into engagement with each other only when the closure member 41 is withdrawn in order to gain access to the interior of the discharge unit 8 and thus also pulls out with itself the two members 25 and 26 which are inserted into the body 18.

On the other hand, such sectors are independent of each other when the closure member 41 is screwed in (Figure 1) precisely to permit the closure member 41 to rotate alone, without the two members 25 and 26 also rotating.

In turn, the circular closure member 41 is so constructed that it can be screwed in and unscrewed only by means of tools, this being in accordance with International standards which make it necessary to resort to these arrangements in order to have access to accessible rotating parts (in this case, the rotor of the discharge pump).

For this purpose, the closure member 41 has a recess 46 and a hexagon to which the tool can be applied, for screwing on and unscrewing the closure member 41.

The mode of operation of the discharge unit 8 of the above-described constitution will now be described hereinafter.

First of all, the first member 25 and the second member 26 are successively introduced into the internal chamber in the body 18. The circular closure member 41 is then screwed on to the front end of the body 18, in the manner described hereinbefore, whereby the projection 42 of the closure member 41 axially compresses the sealing means 39 and therefore thrusts the second member 26 inwardly of the chamber in the body 18 (towards the right in Figure 1).

Consequently, the first member 25 is also thrust axially in the same direction by virtue of the engagement between the circular sectors 29 of the first member 25 and the circular recess 33 in the second member 26, until the sealing means 30 of the first member 25 is pressed against the projection 31 of the body 1 8.

Since at that point the two members 25 and 26 can no longer move axially, this means that any further tightening of the closure member 41 causes the sealing means 39 to be compressed against the internal walls of the body 18 and thus provides for hermetic sealing thereof, thereby to prevent any loss of water outwardly of the discharge unit 8.

The axial extension 28 serves to improve priming of the rotor of the discharge pump 9, insofar as it diverts the air bubbles which are formed, towards the recirculation conduit 21. As already described above, the flexible conduit 7 is provided with a collection vessel 14 below the bottom opening 10 in the tub 5.

In this way, the detergent which is introduced into the tub and which tends to be deposited in the flexible conduit 7 is almost entirely collected on the surface 1 5 of the vessel 14 and passes into the interior of the flexible conduit 7, only to a reduced extent, by virtue of the provision of the raised edge 17. This arrangement ensures that that detergent does not accumulate in the internal corrugations of the flexible conduit 7, which would have prevented it subsequently from being effectively recovered.

In the pre-wash and washing phases, rotation of the drum 6 provides for circulation of the water mixed with detergent through the flexible conduit 7, the discharge unit 8 and the recirculation conduit 21.

It will thus be appreciated how, in this manner, there is improved recovery of the detergent and how this solution makes it possible to re-utilise up to 99% of that detergent.

At the point of connection between the recirculation conduit 21 and the opening 22 of the tub 5, the recirculation conduit is so shaped as to form a further lip 47 which projects inwardly of the tub 5 in the direction shown in Figure 2.

This lip is identical to and performs the same junction as the deflector plate described in above mentioned patent application No. 45717/A-77 and makes it possible to facilitate and improve the circulation of water mixed with detergent in the discharge device according to the invention, by virtue also of the presence of the lip 1 6 of the collection vessel 14.

A further feature of the device is that the rotor 50 is provided with blades 51 of helicoidal shape and that its axis of rotation is aligned with the axis of symmetry of the through opening 27 in the first member 25. In addition, the central boss 52 of the rotor is extended in a pointed arch configuration which extends at least partly into the through opening 27. In relation to helicoidal discharge pumps of conventional type, the blades 51 of the rotor 50 are of an inverse radial profile adapted to discharge water during the operation of the electric pump 9.

This inverse helicoidal profile has a progressively declining curved surface which is arranged to provide a connection between the highest point of the blades (at the position of the central boss 52) and the peripheral surface of the blades.

This particular arrangement and configuration of the rotor 50 improves the self-cleaning action of the discharge unit insofar as the water which is taken in through the connecting means 12 passes through the member 26 which, being of box-like form, does not have surfaces around which any threads which may be present can accumulate. In addition, the extension 28 of the member 25 has its end free and is in the region of greatest turbulence of the circulating water, whereby threads cannot remain thereon.

Finally, it has been found in testing that the pointed-arch configuration of the central boss 52 of the rotor 50 prevents the formation of a region in which the water is relatively calm and in which threads could have accumulated.

Obviously, the rotor of the discharge pump may also be constructed in different ways, without thereby departing from the scope of the present invention.

For example, the pump rotor may comprise a body of elastic material, which is provided with blades of a linear profile, such blades being known per se, the body being disposed adjacent the through opening 27 of the first member 25.

Even this construction provides the self-cleaning action in respect of the discharge unit 8, insofar as any foreign bodies and threads will be discharged directly to the outside by virtue of the elasticity of the blades of the rotor.

It will still be understood however that, whatever the type of rotor, the rotor should be positioned, in the discharge unit, in such a way as to be visible and easily accessible once the members 25 and 26 have been removed.

On the whole, the above arrangements have the advantage that the discharge unit requires inspection at less frequent intervals, although permitting ease of access when required.

The provision of the sealing means 30 prevents water in the discharge phase from seeping between the members 25 and 26 whereby priming of the electrical discharge pump 9 is facilitated and the output of the pump 9 is improved. In addition, the pump 9 provides for discharge with smaller pressure losses, by virtue of the particular form of the blades 51 of the rotor 50 and the fact that the water is thrust into the discharge connecting means 20 in the tangential direction.

Thus the illustrated embodiment can provide a simple and compact self-cleaning discharge unit which does not suffer from the disadvantages described above, by suitably modifying the configuration of the flexible conduit in such a way as to reduce detergent consumption and permit more efficient recovery of the detergent with a lower water temperature. A further advantage of the embodiment is that of being able to inspect the discharge unit easily by having direct access to the rotor of the pump in the event of blockage.

Claims

1. A clothes washing machine having: a washing tub; a drum which is rotatable in the tub; and a discharge device for discharging water from the machine, the discharge device comprising a discharge pump upstream of which there is fixed a hollow housing provided with connecting means for connection to an intake conduit from the bottom of the tub, to a recirculation conduit for recirculating the water from the tub and to a discharge conduit of the machine, wherein that housed within said housing are an annular member provided with an axial extension of circular sector form extending on the opposite side with respect to the pump, and a transfer member of generally cylindrical shape which is provided with openings associated with said connecting means, first sealing means being provided between said annular member and a projection in the interior of said housing and second sealing means being provided between said transfer member and said housing, a frontal closure member being engageable with said housing and said transfer member and being capable of assuming in a closing condition a first position in which said first sealing means is clamped and a following position in which said second sealing means is clamped.

2. A clothes washing machine according to claim 1 wherein said annular member is provided with a series of external circular sectors capable of clipping engagement within a discontinuous annular recess provided in said transfer member.

3. A clothes washing machine according to claim 2 wherein a reinforcement ring is inserted between said first sealing means and said circular sectors.

4. A clothes washing machine according to claim 1, 2 or 3 wherein said second sealing means are housed in a collar portion projecting from the closed end portion of said transfer member.

5. A clothes washing machine according to any one of the preceding claims wherein said closure member is provided with a projection capable of abutting against said second sealing means by way of at least one interposed anti-wear washer member.

6. A clothes washing machine according to any one of the preceding claims wherein said discharge pump is provided with a rotor which has blades of an inverse helicoidal profile and with a central boss which extends in a pointedarch configuration at least partly into a through opening provided in said annular member.

7. A clothes washing machine according to claim 6, wherein the blades of said rotor are of a curved profile which progressively declines from said central boss toward the peripheral surface of said blades.

8. A clothes washing machine according to any one of the preceding claims wherein flexible conduit which is connected between the bottom opening of the tub and the intake connecting means is provided with a vessel for collecting detergent, in a position below said bottom opening, and the interior of said collecting vessel has a lower collecting surface which terminates towards the mouth of said flexible conduit with a raised edge, and an upper lip which projects inwardly of said tub.

9. A clothes washing machine constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.