NZ514244A

NZ514244A - Laundry machine with an inclined frictionally engaged drum

Info

Publication number: NZ514244A
Application number: NZ514244A
Authority: NZ
Inventors: Martin William Myerscough
Original assignee: Monotub Ind Plc
Priority date: 1999-04-08
Filing date: 2000-03-30
Publication date: 2003-05-30
Also published as: WO2000061854A1; AU3568700A; EP1165875A1; GB9908020D0

Abstract

A laundry machine, such as a washing machine, spin drier or tumble drier, including a drum (1) rotatably mounted about an axis, and including a generally open end (8) and a perforated container (3) arranged to be positioned within the drum (1) through the opening (8). A drum engaging surface (40. 40') is provided on the perforated container (3) for frictionally engaging the drum (1) such that the perforated container (3) is rotated with the drum (1). In a preferred example, the friction engaging surface is in the form of an elastic band (40) that is stretched around the outer surface of the perforated container (3), and which is located in a groove on the outer surface of the perforated container.

Description

1 LAUNDRY MACHINE BACKGROUND TO THE INVENTION Conventionally washing machines include a fixed water tank having a top or front opening. A rotatable drum is provided within the tank, the drum having a perforated side wall to allow water from the water tank to enter the drum, and an opening which corresponds generally with the opening in the water tank. The opening of the drum has a diameter smaller than the inside of the drum giving an annular ring around the opening. A door providing a water tight seal closes the openings in the drum and water tank.

In use, a user opens the door, thereby giving access to the interior of the drum, and adds items to be washed through this opening into the drum. The door is then closed and the water tank is partially filled with water to commence the washing cycle. The drum is rotated, thereby moving the items in the drum through the water contained in the tank. Agitators are provided in the drum to enhance this movement. The annular ring around the opening in the drum prevents items from passing through the opening and into the water tank itself and prevents them becoming damaged by contact with a fixed door. After completion of the washing cycle, the water in the water tank is drained away and the drum is rotated at high speed to spin out any excess water. After this the door is opened and the user reaches into the interior of the drum and removes the items which have been washed individually.

To avoid the necessity of removing each washed item individually, attempts have been made previously to collect items together within the rotatable drum, either by using a plastics clip to physically attach items together, for example socks, or a bag made from netting which can be placed into the rotatable drum through the small opening to the drum and removed from the drum after completion of the washing cycle as a single item. Such arrangements have 2 not achieved commercial success, probably because they do not allow a complete washload to be kept together due to their limited volume compared to that of the drum.

In our earlier International Application No WO 98/21393, we disclose and 5 claim a washing machine comprising: a drum rotatably mounted about an axis, and including a generally open front end; a perforated container arranged to be positioned within the drum, the outer surface of the perforated container corresponding closely with the inner 10 surface of the drum, the perforated container having an internal volume substantially equal to that of the drum, and being removable through the front opening of the drum; and, a removable means for at least partially closing the front opening of the drum.

With this arrangement, the items to be washed are provided within a perforated container having almost the same capacity as the drum. Therefore the capacity of the washing machine is not reduced significantly by the inclusion of the perforated container, and the movement of the items, which ensures efficient washing, is not inhibited. |t will be appreciated that this earlier invention is equally applicable to machines for washing clothes and other items and to other washing or laundry machines, such as spin driers and tumble driers.

The perforations on the perforated container allow the free flow of water between the inside of the drum and the inside of the perforated container, and GB 000001234 3 therefore ensures the items are soaked, washed and rinsed in exactly the same way as if the perforated container were not provided.

It is important that the perforated container rotates with the drum, since rotation is required for efficient washing of items, and to remove excess water by spinning. In our earlier application, we disclose fixing the perforated container in the drum by a bayonet or snap-fitting, or by relying on the centrifugal force as the drum is rotated causing the side walls of the container to bow outwardly and engage the side walls of the drum. This requires the container to be formed of a suitably resilient material, and requires high centrifugal forces such as those occurring during a spin cycle.

It has been found that some people may have a problem in lifting and placing a perforated container full of items to be washed into the drum of a washing machine, especially where the perforated container must be aligned angularly with the drum. This may be a particular problem as the drum is generally free to rotate within the washing machine.

SUMMARY OF THE PRESENT INVENTION According to the present invention, a laundry machine comprises a drum rotatably mounted about an axis, and including a generally open end, a perforated container arranged to be positioned within the drum through the opening, and a drum engaging surface comprising a ring of engaging material extending around the outer surface of the perforated container for frictionally engaging the drum such that the perforated container is rotated with the drum.

With the machine of the present invention, the perforated container may be placed into the drum at any angular orientation with reference to the axis of rotation of the drum, yet the perforated container will be coupled to the drum such that rotation of the drum causes corresponding rotation of the container.

AMENDED SHEET 03-04-2001 GB 000001234 4 This makes it much easier to position the container within the drum than where the container is fitted to the drum by a fixing which is angle dependent, such as a bayonet fixing. Further, the container can be coupled to the drum at all times, not only when there is a high centrifugal force.

The drum engaging surface may act as a seal such that water dispelled from the perforated container cannot pass along the side of the container between this and the drum past the drum engaging surface. In this case, it is preferred that the drum engaging surface is provided around the perforated container near the end of the container which, in use, is positioned closest to the open end of the drum. In this way, water expelled from the container is constrained to move within the drum towards the rear of the drum, and cannot pass to the front opening of the drum.

It is preferred that the drum engaging surface is in the form of an elasticated band that is stretched over the container, and is then released to grip the side 15 of the container. In this case, it is preferred that the side wall of the container includes a groove within which the band is received, thereby ensuring the correct positioning of the band. It is preferred that the band has a "D"-shaped section. This gives the optimum seal and contact between the AMENDED SHEET drum and the container. Where the band has a hollow section, the band may better conform to the surfaces against which it engages than will be the case if the band is solid. Therefore, a hollow section is preferred.

The drum engaging surface may be formed of a suitable plastics to rubber material, such as neoprene. The material should be capable of withstanding the high temperatures encountered during the cycle of the laundry machine, and should be resistant to the detergents used. Preferably the drum engaging surface is resilient or deformable to give optimum engagement with the drum.

The axis around which the drum rotates may be a horizontal axis, although it is preferred that the axis is inclined to the horizontal. Where the drum is inclined, water within the drum will remain below the open end of the drum, and therefore there is no need to provide a water tight seal to contain the water.

The laundry machine preferably includes a removable means for at least partially closing the front end of the drum. This prevents items which are being washed from being dispelled from the drum.

As the perforated container is removable from the drum, the removable closure means may be an integral part of the perforated container. In this case, the closure means may be an end surface of the perforated container which coincides with the open end of the drum, and in this case may be a surface which extends over substantially the entirety of the opening of the drum. Where the end of the perforated container comprises a surface extending over the entire opening of the drum, a separate opening is provided in the perforated container to allow items to be added to and removed from the perforated container. This opening may be provided by a hinge extending along the edge of the perforated container parallel to the longitudinal axis of the perforated container. In this case the perforated container can be opened 6 out easily once removed from the drum to allow easy access to the items in the perforated container. It is however preferred that the end surface of the perforated container includes an opening through which items to be washed can be added or removed from the perforated container, and in this case the 5 end surface of the perforated container does not extend over the entirety of the opening of the drum, but gives only a partial closure. This allows items to be added to and removed from the perforated container when this is provided within the drum of the laundry machine, and in particular allows items to be added and removed during the washing cycle. In this case it is preferred that 10 the opening in the end of the perforated container is a generally central opening, thereby giving an annular cover which extends around the side of the opening in the front of the drum. This is advantageous as any items being washed which may approach the front end of the drum during washing will be close to the side of the drum due to the rotation of the drum.

Alternatively or additionally, the removable means may be in the form of a separate cover which is provided to close the end of the drum. This cover can be provided either on the drum itself, or on the perforated container, in which case the cover will rotate with the drum. The cover may be hinged to the drum or perforated container.

Although the drum is preferably generally cylindrical, the drum advantageously has a slightly larger diameter at its rear end than at its front opening end. With this arrangement, when the drum is rotated at high speed to spin water, the water will be forced towards the back of the drum where it may be collected easily. The drum may have a solid side wall, or the side 25 walls may be apertured so the drum has a frame like appearance.

Preferably the perforated container is of a resilient material so that the perforated container retains its shape. The perforated container is preferably 7 generally cylindrical, but advantageously is slightly tapered with the closed rear end having a smaller diameter than the front end. This slightly frusto-conical shape facilitates easy positioning of the perforated container in and removal from the drum.

Advantageously, the perforated container includes projections projecting radially inwardly of the perforated container. In use these projections, or agitators, lifts the items in the perforated container as it is rotated. With this arrangement, the drum can have a smooth side wall to allow easy insertion and removal of the perforated container. However the raised projections on 10 the inside of the perforated container act to provide sufficient agitation to the clothes during the washing cycle to clean the clothes efficiently.

Water may be removed by centrifugal force during a spinning operation forcing the water to the outside of the drum where it is collected and removed, for example through an outlet point mounted on a fixed arm within the 15 rotatable drum. Alternatively, holes may be provided on the back surface of the drum at a height below the front end of the drum so that water is discharged through the holes.

Whilst the present invention is described in relation to a washing machine, it will be appreciated that this term has a wider scope than merely a machine for 20 actually washing items. In particular, the term covers machines used for dying items and to driers such as tumble driers.

BRIEF DESCRIPTION OF THE DRAWINGS Examples of the present invention will be described in accordance with the accompanying drawings, in which: 8 Figure 1 shows a cross-section through an example of a washing machine including a perforated container; Figure 1a shows an enlarged cross-section of the region around the friction engaging surface; Figure 2 shows an alternative perforated container; Figure 3 shows an alternative perforated container provided in the machine of Figure 1; and, Figure 4 shows agitators.

DETAILED EXAMPLE OF ONE EMBODIMENT OF THE PRESENT 10 INVENTION Figure 1 shows a cross-sectional view taken through the axis of a generally cylindrical drum of an example of a washing machine according to the present invention. The cylindrical drum includes a side wall 1 and a circular back end wall 7 defining a drum with an open front 8. The drum is mounted on an axial 15 spindle 2 for rotation about its axis which is inclined to the horizontal at an angle of about 20°. The back surface 7 of the drum includes a plurality of outlet holes 5. The lowest outlet hole 5 is below the height of the lip of the open front 8.

The drum also includes a removable perforated container 3 which is 20 positionable within the drum through the front opening 8 of the drum, and which is removable through the front opening 8. The perforated container 3 is shaped and dimensioned to closely correspond to the internal walls of the drum so the internal volume of the perforated container 3 is only slightly smaller than that of the drum. The perforated container 3 is generally tapered 9 so that the front end including the opening has a larger diameter than the rear closed end. This assists in the insertion of the perforated container 3 into the drum.

The perforated container 3 includes a groove around the outer surface 5 towards the front end of the perforated container 3 which receives a ring of rubber 40 around its outer surface. Typically, the ring 40 has a width of about 1 cm. As shown in Figure 1a, the ring 40 has a hollow D-shaped section. The ring 40 may be stretched over the side of the container 3, and released to retract into the groove in the side wall of the container 3. When the container 10 3 is located within the drum 1, the rubber 40 engages the inner surface of the drum 1. This frictional engagement between the container 3 and the drum 1 ensures the container 3 rotates with the drum 1. As the coupling between the container 3 and the drum 1 is merely by frictional engagement, the perforated container 3 may be inserted into the drum 1 at any angular orientation, and 15 there is no requirement to make relative angular adjustments between the container 3 and drum 1.

The perforated container 3 has perforations through which water in the drum can pass into the perforated container 3, and through which water in the perforated container 3 can drain into the drum. The perforations are in the 20 form of elongate slits having a width of about 2mm and a spacing of about 2cm.

To help centre the perforated container 3 within the drum 1, a projection 9 is provided on the rear face of the drum 1 which is received within an axial recess 10 in the rear face of the perforated container 3.

The open end of the perforated container 3 includes an annular ring 4 giving a reduced diameter opening to the perforated container 3. The ring 4 ensures PCT/GB0O/O1234 that clothes do not fall out of the perforated container 3 during the washing cycle.

As shown in Figure 2, in one example the perforated container 3 includes a hinged portion extending along the side of the perforated container 3 5 generally parallel to the longitudinal axis of the perforated container 3. The perforated container 3 also includes a clasp to hold the perforated container 3 in its generally cylindrical shape. In this way, the clasp may be undone and the perforated container opened about the hinge to allow easy access to the contents of the perforated container.

In an alternative example, as shown in Figure 3, the perforated container includes a completely closed front end, and an opening 25 in the side wall. As the side wall corresponds closely with the inside of the drum, items contained within the perforated container are not able to fall from the perforated container through the opening into the drum. With this 15 arrangement, items to be washed are added to the perforated container through the opening 25 before the perforated container is placed in the drum. When full, the perforated container is lifted into the drum, effectively closing the perforated container so all the items to be washed are maintained within the perforated container. With this arrangement, it is not possible to add 20 items after the washing cycle has begun.

A shroud 6, inclined to the horizontal by the same angle as the drum is provided to a vertical front opening of the machine. The opening of the machine is closed by a door 11. This closure does not form a watertight seal but acts merely to prevent splashes during the washing cycle. in use, clothes are placed into the perforated container 3, either before the filled perforated container 3 is put in the cylindrical drum through the front opening 8, or when the perforated container 3 has been positioned in the 11 drum. Water, which may include washing detergent is introduced to the drum through the spindle 2. The water enters the perforated container 3 through the perforations in the perforated container to wet the clothes. Other systems for introducing water are known, for example by providing longitudinal channels 5 along the length of the perforated container including holes, such that water is pumped into the channels and showers through the holes into the container. Such a system is disclosed in our earlier application GB 9808606.9.

As the lowermost outlet 5 is below the height of the lip of the open front end 8, and due to the inclination of the drum, water entering the drum can rise to the 10 level of the lowermost outlet 5, the lowest drainage point, and any additional water will drain through the lowermost outlet 5. As the lowest drainage point is below the level of the lip of the open front end 8, and providing the outlets 5 are of a suitable size the water level will not rise to that of the lip of the open front end 8.

As it is not necessary to close the front end 8 of the drum, it is possible to add garments after the wash cycle has begun.

When the water and clothes are in the perforated container 3 within the cylindrical drum, the drum is rotated about its inclined axis, thereby agitating the clothes in the water to wash them. Due to the inclination of the drum, 20 water passes through the holes 5.

The rear 7 of the drum is positioned within a recess of a water collector 12. As water is discharged through the holes 5 in the back of the drum, this will be collected in the water collector 12, and will fall, under gravity, to the bottom of the water collector to be dispensed through the outlet 13. The rate at which 25 the water is discharged from the drum is such that there is no need to provide a hermetic seal between the edge of the collector 12 and the outside of the drum.

GB 000001234 12 During the washing cycle, the water may be recirculated, and may pass through a heater (not shown) to reheat the water, before being reintroduced to the drum through the inlet 2. This ensures that the water within the drum is maintained at the required temperature. When it is desired to dispense the water, the water from the outlet 13 is not recirculated, but is merely dispensed down a drain.

The perforated container 3 may be provided with agitators to lift the clothes within the drum. As shown in Figure 4 agitators are in the form of a projection 30 which extends from the back of the container 3 circumferentially around the container and towards the front of the container and return to the back of the container.

The base of the agitator 30 is generally triangular in cross-section, having a maximum height from the side walls near the base of the container, and a minimum height near the front of the container. The cross-sectional shape of the agitator 30 may be other than triangular. The agitator 30 has rounded apexes to prevent damage to the clothes. Although only one agitator 30 is shown, two or more agitators may be included.

Because the agitator 30 includes components extending towards the front of the drum in both a clockwise and anti- clockwise circumferential direction, on rotation of the drum, articles within the drum are lifted and drawn towards the front of the drum upon rotation of the drum in either direction.

AMENDED SHEET 03-04-2001 GB 000001234

Claims

13 CLAIMS

1. A laundry machine comprising a drum (1) rotatably mounted about an axis, and including a generally open end (8), a perforated container (3) arranged to be positioned within the drum (1) through the opening (8), and a drum engaging surface (40, 40') comprising a ring of engaging material extending around the outer surface of the perforated container (3) for frictionally engaging the drum (1) such that the perforated container (3) is rotated with the drum (1). 10

2. A machine according to claim 1, in which the drum engaging surface (40, 40') is formed of rubber.

3. A machine according to claim 1 or claim 2, in which the ring (40) has a D-shaped section.

4. A machine according to any one of the preceding claims, in which the perforated container (3) has a groove for receiving the ring (40) of engaging material.

5. A machine according to any one of the preceding claims, in which the ring (40) of engaging material is in the form of a stretchable band.

6. A machine according to any one of the preceding claims, in which the 20 axis around which the drum (1) rotates is inclined to the horizontal.

7. A machine according to any one of the preceding claims, further comprising a removable means (11) for at least partially closing the front opening of the drum (1). AMENDED SHEET GB 000001234 14

8. A machine according to ciaim 7, in which the removable closure means is an integral part of the perforated container (3).

9. A machine according to claim 7, in which the removable closure means (11) is a surface which extends over substantially the entirety of the opening of the drum (1).

10. A machine according to any one of the proceeding claims, in which the perforated container (3) includes a hinge extending along the edge of the perforated container (3) parallel to the longitudinal axis of the perforated container (3) to allow the perforated container (3) to be opened once removed from the drum (1).

11. A machine according to any one of claims 1 to 9, in which the end surface of the perforated container (3) includes an opening through which items to be washed can be added or removed from the perforated container (3).

12. A machine according to claim 11, in which the opening in the end of the perforated container (3) is a generally central opening.

13. A machine according to any one of the preceding claims, in which the perforated container (3) is made of a resilient material so that the perforated container (3) retains its shape.

14. A machine according to any one of the preceding claims, in which the perforated container (3) is slightly tapered with the closed rear end having a smaller diameter than the front end.

15. A machine according to any one of the proceeding claims, in which the perforated container (3) includes projections (30) projecting radially inwardly AMENDED SHEET 03-04-2001 GB 000001234 15 of the perforated container (3) which, in use, lifts the items contained in the perforated container (3) as it is rotated. AMENDED SHEET