GB2432593A

GB2432593A - Washing machine drum

Info

Publication number: GB2432593A
Application number: GB0523981A
Authority: GB
Inventors: Andrew Martin Reason; Mario Rabaiotti
Original assignee: Andrew Reason Ltd
Current assignee: Andrew Reason Ltd
Priority date: 2005-11-25
Filing date: 2005-11-25
Publication date: 2007-05-30
Also published as: GB0523981D0

Abstract

The drum 100, which may be formed of an elongate rectangular piece of metal, is a cylindrical receptacle rotatably mounted within the washing machine. An opening 102 allows loading and unloading of laundry. At least one aperture 206 allows liquid purged from the laundry to be expelled from the receptacle. The drum includes guide means 106 such as drain channels to guide the purged liquid, upon rotation of the drum, toward the aperture. The guide means 106 may be fed by a plurality of elongate parallel guide channels 104 arranged in a herring-bone configuration. The guide means may slope from a shallow start point to a deep end point at the aperture 206.

Description

Washing Machine Drum The present invention relates generally to a drum

for a laundry appliance, and more specifically to an improved drainage system for a laundry appliance.

In general, a washing machine follows a sequence of pre-set actions depending on a program selected by a user. Typically, a washing machine comprises a drum into which laundry is placed. During a wash program the drum fills with water and is then caused to rotate so as to cause an agitating fin therein to agitate' the laundry. Next, the dirty water (and detergent) is drained and the drum spins to remove most of the water. The drum then refills with clean water and is again caused to rotate so as to agitate the laundry and ensure it is thoroughly rinsed. Finally, the drum is again drained and caused to spin at high speed sO as to remove as much water as possible from the laundry at the end of the cycle.

In conventional washing machines, a drum generally comprises two main parts, the first being an inner perforated cylinder, into which the laundry is placed, housed within a larger water-tight cylinder, arranged such that the inner cylinder can rotate therein. Clearly the usable capacity of such a drum is limited by the need for co-axial cylinders with a gap therebetween.

It is therefore an object of the invention to provide a washing machine drum of increased capacity, without proportionately increasing the overall size of the appliance.

In accordance with the present invention there is provided a drum for a washing machine, the drum comprising: a generally cylindrical receptacle which is rotatably mounted within a washing machine housing and has an opening for loading and unloading laundry, wherein said receptacle is defined by a substantially solid outer wall having at least one aperture therein, and means for guiding liquid purged from said laundry upon rotation of said drum towards said at least one aperture such that said liquid is expelled from said receptacle via said at least one aperture.

Preferably, the means for guiding liquid purged from the laundry upon rotation of the drum towards said at least one aperture comprises a channel, preferably having a proximal deep end and a distal shallower end, relative to said at least one aperture, such that rotation of the drum forces the liquid from the shallower end to the deep end and said liquid is expelled from the receptacle via said at least one aperture.

Beneficially, a plurality of said channels are provided in respect of said at least one aperture.

Beneficially, said drum is provided with a plurality of apertures and one of more respective channels are preferably provided to guide said liquid purged from said laundry upon rotation of said drum towards each of said plurality of apertures. Preferably, a plurality of said channels guide said liquid purged from said laundry upon rotation of said drum towards said plurality of apertures. A plurality of said channels may be provided in a herringbone configuration.

Preferably, a valve is provided within said at least one aperture to control the flow of said liquid through said aperture and in the case where said drum comprises a plurality of apertures, each said aperture is beneficially provided with a valve. The valve(s) may be actuated by mains water pressure or by a centrifugal force generated by the rotation of said generally cylindrical receptacle.

Beneficially, said opening comprises a hatch, said hatch being liquid light when in a closed position and permitting the loading and unloading of laundry when in an open position.

Thus the above mentioned object is achieved by providing a drum consisting of a single cylinder that is generally substantially water-tight under normal conditions, yet can purge water therefrom during a spin cycle', thereby removing the need for co-axial cylinders as described with reference to the prior art and as such increasing the usable capacity of the drum, although co-axial cylinders may still be used under some circumstances.

The present invention extends to a washing machine comprising a drum according to any one of the preceding claims, rotatably mounted in a housing, drive means for rotating said drum during a wash cycle, and control means for controlling one or more parameters of a wash cycle, wherein said control means comprises means for interrupting a wash cycle and permitting access to said opening in said drum.

Preferably, said opening is provided in a side wall of said drum and said control means is arranged and configured to halt rotation of said drum so as to interrupt a wash cycle when said opening is at or close to top dead centre (TDC) of said drum, such that access to said opening can be permitted whilst retaining liquid within said drum.

Thus, the configuration of an exemplary embodiment of the invention enables a user to pause a wash cycle and open the drum, which is not possible with conventional designs.

These and other aspects of the present invention will be apparent from, and elucidated with reference to, the embodiment described herein.

An embodiment of the present will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a representation of a flat, unassembled drum according to an exemplary embodiment of the present invention; Figure 2a shows a cross-sectional representation of the sum gradient of the channels; Figure 2b is a schematic representation of the drum from Figure 1 as assembled; Figure 3 is a schematic drawing of a first exemplary dump valve for use in an arrangement according to an exemplary embodiment of the present invention; and Figures 4a and 4b are schematic front and cross-sectional views respectively of a second exemplary dump valve for use in an arrangement according to an exemplary embodiment of the present invention.

Referring to Figure 1 of the accompanying drawings, a drum 100 according to an exemplary embodiment of the invention is formed of an elongate rectangular piece of metal, which is bent round and the ends joined together to form an open cylinder. There is a suitably sized, possibly, but not necessarily, substantially rectangular aperture 102 located approximately centrally in terms of the length and width of the metal piece forming the drum 100, that provides an opening for placing laundry into and removing laundry from, the drum 100 when assembled 1 OOb. A plurality of elongate drain channels 106 are provided in the piece of metal 100, which channels 106 run laterally across the piece of metal. Referring to Figure 2a of the drawings, the drain channels 106, when viewed cross-sectionally all slope in the same direction from a shallow start point 201 to a distal deep end point 209. Each deep end point 209 defines a valve housing 108 comprising a circular purging aperture 206 located centrally in an offset circular recess 208, such that if the piece of metal were to be held in a substantially horizontal orientation and a quantity of liquid were introduced to a drain channel 106 at the shallow start point 201 (or indeed at any intermediate point along its length), it would flow due to gravity from the point of introduction to the deep end point 209 and through the circular purging aperture 206 located centrally in an offset circular recess 208. In Figure 2a, the sum gradient that is defined by the configuration of all the drain channels 106 can clearly be seen.

A tapered portion 210 of the drain channel 106, located behind the purging aperture 206 (relative to the shallow start point 201), provides a reverse gradient that ensures that most liquid that is directed towards the purging aperture 206 exits at that point. Referring back to Figure 1, the elongate drain channels 106 are each fed by a respective plurality of elongate, parallel guide channels 104, arranged in banks and having substantially the same sum gradient as the drain channels 106. The guide channels 104 run into a respective drain channel 106 at an angle of substantially say, 450 and any two adjacent banks of guide channels 104 are arranged in a herring-bone configuration as shown.

Referring now to Figure 2b, the drum 100 is shown, in its assembled form, i.e. a cylindrical drum 1 OOb. As the drum 1 OOb rotates about its central axis 254 with an angular velocity 250, a centrifugal force 252 (F) is created, as shown. It will be apparent from Figure 2b that this force 252 acts perpendicular to a plane on the circumference of the cylinder lOOb and will cause any liquid inside the drum to move to the inner walls thereof and into the guide channels 104. The water then flows from the guide channels 104 into the respective drain channels 106 and then the valve housing 108. Thus, water inside the drum I OOb is directed, during a spin cycle, to specific points, i.e. the valve housings 108 provided at the wall thereof, and as such, means such as a dump valve can be provided at these points to expel the directed liquid as a by-product of the spin-cycle.

Referring now to Figures 3 and 4 of the accompanying drawings, a cross-sectional perspective representation of two respective exemplary embodiments of a dump valve 300 are shown.

The dump valve 300 comprises an upper section and a lower section separated by a cylinder seperator 314 within which is provided a stem seal 31 4a, through which passes a valve stem 303. In the upper half of the valve, the piston head 304 is provided with a piston head seal 304a that provides a liquid-tight seal between itself and the surrounding inner face of the wall 310 of the upper section. The cylinder separator 314 may be formed integrally with the wall 310, as shown in Figure 4 of the drawings. A fluid inlet/outlet port 410 is provided in the cylinder wall 310, as shown in Figure 4a of the drawings. At the top of the upper section there is provided a lid 308 that substantially follows the contours of a side wall 310 and further is provides a limit point for how far the piston 302, 303, 204 may travel in that direction. An aperture 312 is provided in the side wall 310, which provides an external connection to the mains water supply. A compressible spring 306 provided in cooperation with the piston which acts to return the piston to its equilibrium position when the valve is closed.

The valve piston stem 303 extends downwardly into the lower section of the valve and terminates in a plug 302, the lower outer edges of which are tapered inwardly to provide a seal between the piston and the drum wall when the valve is closed. The seal may be broken and the valve opened by raising the piston. As shown in Figure 3, a concentric collar 318 may be provided around the lower end of the valve, the collar 318 surrounding the piston head 302 and being connected to the underside of the piston stem seal 31 4a at the top and connected to the inner face of the drum lOOb at the bottom. A plurality of generally arch shaped apertures 320 are formed around the bottom of the collar 318 to allow ingress of water from the drum lOOb when the piston 302, 303, 304 is raised and the valve is therefore open. This opening action is facilitated by mains water pressure entering the upper section of the valve through the aperture 312, thereby exerting pressure on the lower face of the piston head seal 304a that provides a liquid-tight seal between itself and the surrounding inner face of the wall 310 of the upper section so as to force the piston 302, 303, 304 upwards towards its limit at the lid 308.

Whilst in this position water may pass from inside the drum 1 OOb, through the plurality of arch shaped apertures 320 and be purged from the drum lOOb through the purging aperture 206.

When the mains pressure is no longer present the spring 306 causes the piston to return to its closed position.

It should be noted that the above-mentioned embodiment illustrates rather than limits the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word "comprising" and "comprises", and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. The invention may be implemented by means of hardware comprising several distinct elements. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

CLAIMS: 1. A drum for a washing machine, the drum comprising a

generally cylindrical receptacle which is rotatably mounted within a washing machine housing and has an opening for loading and unloading laundry, wherein said receptacle is defined by a substantially solid outer wall having at least one aperture therein, and means for guiding liquid purged from said laundry upon rotation of said drum towards said at least one aperture such that said liquid is expelled from said receptacle via said at least one aperture.

2. A drum according to claim 1, wherein said means for guiding liquid purged from the laundry upon rotation of the drum towards said at least one aperture comprises a channel, preferably having a proximal deep end and a distal shallower end, relative to said at least one aperture, such that rotation of the drum forces the liquid from the shallower end to the deep end and said liquid is expelled from the receptacle via said at least one aperture 3. A drum according to claim 2, wherein a plurality of said channels are provided for guiding said liquid purged from said laundry upon rotation of said drum towards said at least one aperture.

4. A drum according to any preceding claim, wherein said drum is provided with a plurality of apertures and one of more respective channels are provided to guide said liquid purged from said laundry upon rotation of said drum towards each of said plurality of apertures.

5. A drum according to claim 4, wherein a plurality of said channels guide said liquid purged from said laundry upon rotation of said drum towards said plurality of apertures.

6. A drum according to either of claims 3 to 5, wherein said plurality of said channels are provided in a herringbone configuration.

7. A drum according to any preceding claim, wherein a valve is provided within said at least one aperture to control the flow of said liquid through said aperture.

8. A drum according to claim 7, wherein each said aperture in said drum is provided with said valve.

9. A drum according to either or claims 7 or 8, wherein said valve is actuated by mains water pressure.

10. A drum according to either of claims 7 or 8, wherein said valve is actuated by a centrifugal force generated by the rotation of said generally cylindrical receptacle.

11. A drum according to any preceding claim wherein said opening comprises a hatch, said hatch being liquid light when in a closed position and permitting the loading and unloading of laundry when in an open position.

12. A drum as herein before described with reference to the accompanying drawings.

13. A washing machine comprising a drum according to any one of the preceding claims, rotatably mounted in a housing, drive means for rotating said drum during a wash cycle, and control means for controlling one or more parameters of a wash cycle, wherein said control means comprises means for interrupting a wash cycle and permitting access to said opening in said drum.

14. A washing machine according to claim 13, wherein said opening is provided in a side wall of said drum and said control means is arranged and configured to halt rotation of said drum so as to interrupt a wash cycle when said opening is at or close to top dead centre (TDC) of said drum, such that access to said opening can be permitted whilst retaining liquid within said drum.