WO2006131709A1

WO2006131709A1 - Improvements in and relating to washing machines

Info

Publication number: WO2006131709A1
Application number: PCT/GB2006/002029
Authority: WO
Inventors: John Herbert North
Original assignee: John Herbert North
Priority date: 2005-06-08
Filing date: 2006-06-05
Publication date: 2006-12-14
Also published as: GB0610999D0; GB2426980A

Abstract

A washing machine comprising a cabinet (10) containing a stationary- cylindrical drum (20) and a door (36) for closing a circular opening (32) in a wall (18) of the cabinet and which when closed prevents fluid from entering or leaving the open end (26) of the drum and when open gives access to the interior of the drum. A window (42) in the door registers with an opening in the end of the stationary drum when the door is closed. A first annular sealing member (46) protrudes from the rear (38) of the door around the window so as to protrude into the circular opening in the cabinet when the door is closed and a second annular sealing member (44) is provided around the circular opening in the cabinet which is engaged by the first sealing member when the door is closed, to form a fluid tight seal between the door and the cabinet. The open end of the drum is sealed to the cabinet around the opening in the cabinet and by sealing the door to the cabinet the drum is effectively sealed against ingress or egress of fluid. By sealing between the door and the cabinet instead of between the window and the dram, the opening in the dram can be larger than has hitherto been the case and a larger basket (56) can be fitted in the drum.

Description

Title: Improvements in and relating to washing machines

Field of invention

This invention concerns washing machines and in particular a door for a washing machine in which a drum into which articles are placed during the washing process is mounted for rotation about a horizontal axis within the machine, and when closed the door provides a fluid seal and when open gives access to the drum.

Background to the invention

The drum is normally mounted within a cabinet and an opening in the latter gives access to the drum for loading and unloading articles. Hitherto the door has included a central glass window through which the washing process can be viewed.

Conventionally the doors have been side-hung with a hinge on one side and a door catch on the other, and typically the hinge and catch have been interchangeable to allow left and right hinging.

To simplify the sealing of the door to the drum, hitherto the opening in the drum has been somewhat smaller than the opening in the cabinet and the glass window has been constructed as a truncated cone and has protruded inwardly from the rear of the door when the latter is closed, and an annular seal has been provided around the opening in the drum within which the tapering surface of the frusto conical glass window is a sealing fit.

It has been proposed to surround the rotatable drum with a stationary drum and to locate a removable basket within the drum and to locate articles to be washed, within the basket. If the basket is to be removed from the rotatable drum, the basket must be capable of fitting through the opening therein.

As a consequence although the cabinet opening which is closed by the door could allow a larger basket to be fitted, the maximum size of basket is dictated by the smaller drum opening.

In addition it has also been proposed to pressurise the outer drum during washing and drying cycles in both a positive and a negative sense, and in order to prevent distortion of a door due to such fluctuations in drum pressure, it is necessary to strengthen the conventional door thus increasing its weight, and the conventional hinge has been found insufficient both to support the increased weight and to resist deformation of the door due to positive or negative pressurisation of the drum.

It is therefore an object of the present invention to provide an improved washing machine and door therefor, which overcome these problems.

Definition

The expression washing machine as employed herein is intended to include machines which solely perform a washing and rinsing function as well as machines which perform washing, rinsing and drying functions.

Summary of the invention

According to one aspect of the present invention a washing machine comprises a cabinet containing a stationary cylindrical drum and a door for closing a circular opening in a wall of the cabinet and which when closed prevents fluid from entering or leaving the open end of the drum and when open gives access to the interior of the dram, wherein: a) the door is hinged to the cabinet and has part of a door closing catch mechanism at a diametrically opposite position,

b) a window of transparent material is provided in the door which registers with an opening in the end of the stationary drum when the door is closed,

c) a first annular sealing member protrudes from the rear of the door around the window so as to protrude into the circular opening in the cabinet when the door is closed,

d) a second annular sealing member is provided around the circular opening in the cabinet which is engaged by the first sealing member when the door is closed, to form a fluid tight seal between the door and the cabinet, and

e) the open end of the drum is sealed to the cabinet around the opening in the cabinet, so that by sealing the door to the cabinet the drum is effectively sealed against ingress or egress of fluid.

The window may be a frusto conical protrusion as is conventional, but by sealing between the door and cabinet, instead of the window and the drum, the opening in the drum can be larger than has hitherto been the case, and likewise a larger basket can be fitted in the drum.

Typically a gasket seal is provided around the circular opening in the cabinet and the annular sealing member on the rear of the door is received in and seals to the gasket seal.

Typically the annular sealing member on the rear of the door is in the form of a frusto conical shell, and the frusto conical wall thereof co-operates with the gasket seal.

Where in use the drum is to be subjected to pressures above and below ambient, the gasket seal is designed to resist fluid ingress into, and egress from, the drum. Typically the drum is resiliently supported within the cabinet to accommodate vibration as non-concentric washing loads rotate, and to this end the open end of the drum is extended towards the opening in the cabinet, which in use is closed by the door, by a cylindrical bellows. Preferably the said second annular sealing member is provided around the end of the bellows facing the door.

According to another aspect of the invention the hinge comprises a first part which is secured to or is integrally formed with the door housing, a second part which is secured to or forms part of the cabinet, and a pin which joins the two hinge parts and allows relative pivoting therebetween, wherein the length of the pin and the two hinge parts is sufficient to support the weight of the door and prevent it from distorting under pressure differentials thereacross.

Typically the axial length of the hinge equates to 50% of the diameter of the opening in the cabinet which is closed by the door, so as to be capable of resisting distortion of the door due to the pressure differentials.

Typically the door catch mechanism extends parallel to the hinge axis albeit on the diametrically opposite region of the door.

Typically the axial length of the door catch mechanism is also of the order of 50% the diameter of the opening in the cabinet, so that the door catch mechanism also assists in resisting any distortion of the door due to pressure differentials thereacross.

The door catch is preferably electromagnetically operable and when the machine is operating preferably an interlock prevents the door from being opened. Preferably the door catch includes a manual override device to enable it to be opened if the power fails.

Preferably a second drum is rotatably mounted within the stationary drum and articles to be washed are put in a basket which in use is inserted into the second drum. The invention will now be described by way of example with reference to the accompanying drawings, in which: -

Fig 1 is a side elevation partly in cross section of a washing machine incorporating both aspects of the present invention, and

Fig 2 is a front elevation of the washing machine of Fig 1 which illustrates the second aspect of the invention.

Detailed description of the Figures

Although referred to as a washing machine, the machine illustrated may comprise a combined washing and drying machine.

In the drawings a washing machine cabinet 10 has a base 12, rear wall 14, top 16, front wall 18 and side wall (not shown).

Mounted within the cabinet is a stationary cylindrical drum 20 supported by a pneumatic spring 22 between it and the base 12, and a helical spring 24 between it and the top 16. Other helical springs (not shown) may be located between the drum 20 and the side walls of the cabinet.

The drum 20 is mounted with its axis at a shallow angle, typically in the range 5° to 20°, to the horizontal.

The end of the drum 26 which is closest to the front cabinet wall 18 is open, whereas the other end 28 is solid and load bearing. Likewise the cylindrical wall 30 is also solid and sufficiently strong as to maintain its shape and configuration even when loaded with garments to be washed and water. The open front end 26 generally registers with a circular opening 32 in the front wall 18 of the cabinet and a cylindrical bellows 34 is sealingly secured at one end around the opening 26 and at its other end around the opening 32. As shown in Fig 1, the bellows distorts to accommodate the misalignment between the opening 26 and the opening 32, due to the angled mounting of the drum 20 within the cabinet 10.

Typically the cabinet and dram are formed from metal such as steel and the bellows may also be formed from a metal such as steel, or may be made from a plastics material or rubber and plastics composition material. However if the bellows is constructed from a material which could distort due to an increase or decrease in pressure within the drum (when the opening 32 is closed) relative to the ambient pressure, the bellows may to advantage be reinforced by rings of a rigid material which are accommodate within the grooves or the ridges of the bellows and are secured or bonded to, or integrally formed with, the material forming the bellows so that the latter is capable of limited axial movement (as permitted by the corrugated nature of the bellows wall), but the bellows is largely prevented from radial distortion in either direction.

The opening 26 is closeable by a door assembly 36. This latter comprises a generally circular flat load bearing door panel 38 (see Fig 2) having a central circular opening 40. A glass or perspex transparent window 42 is sealed to the panel 38 and closes the opening 40. The window may be flat but in order to increase its strength and resistance to bending or distortion it may (as shown in Fig 1) extend as a hollow frusto-conical protrusion from the rear of the panel 38, partly into and trough the opening 32 when the door assembly 36 is closed. The window enables a user to see into the interior of the dram to ascertain the state of a wash programme and to ensure that the machine is functioning in an expected manner.

Unlike conventional washing machine configurations, the rearwardly protruding window does not from part of the fluid seal between the door assembly 36 and the dram. Instead a first annular sealing member 44 is provided around the circular opening 32 where the bellows 34 joins the front cabinet wall 18 and a second annular sealing member 46 is provided on the inside face of the door panel 38, concentrically located relative to the circular window 42 outboard of the opening 40, so as to register with the first sealing member 44 when the door assembly is closed onto the front cabinet wall 18.

Either one or both of the first and second sealing members may be formed from resiliently deformable material such as a plastics material or rubber and plastics composition material.

In a preferred arrangement one of the sealing members is formed from resiliently deformable material (such as aforesaid) and the other is formed from a rigid material such as a hard generally rigid plastics or rubber and plastics composition material, or from metal such as steel.

Concentrically within the drum 20 is mounted a second inner cylindrical drum 48 spaced from the interior of the drum 20 and like the latter possessing a rear end 50 and cylindrical wall 52 which is perforated to provide a fluid path for liquid or gas/air between the interiors of the two drams 20, 48.

The walls 50 and 52 are structurally strong enough to prevent distortion or bending due to forces imposed on the inner dram during washing.

The front end 54 of the inner dram 48 which registers with the open end of the outer dram 26, is also open to allow a wash basket 56 to be inserted and removed as required. The basket is typically constructed from wire or a semi-rigid plastics thread, typically woven in know manner to form the cage-like basket 56.

The basket may include a woven mesh circular closure (not shown) which is hinged or otherwise securable to the open end of the basket 56, so that the open end can be closed after items to be washed have been inserted, and opened when required to allow the washed items to be removed.

In order to prevent the basket 56 from moving out through the open end 52 of the inner dram 48, while the latter is rotated, a circular closure member 58 may also be provided, for securing to the open end of the basket, to at least partially close it and prevent the basket 56 from moving axially within the drum 48. Typically the dram closure 58 is an annular plate (as depicted) which may be hinged to the inner dram 48.

An electric motor 60 is mounted on the exterior of the outer dram 20, typically so as to occupy the space below the lower surface of the dram 20 and the base 12 of the cabinet 10, as shown in Fig 1.

Drive is transmitted from the motor to the inner dram by means of an endless belt 62 which passes around a drive pulley 64 on the motor output shaft 66 and a driven pulley 68 on a shaft 70 which extends through and is supported by a bearing 72 mounted in the centre of the closed end 28 of outer drum 20 and is secured at its inboard end to a plate assembly 74 secured to the centre of the closed end 50 of the inner dram 48.

The bearing 72 is preferably a combined thrust and radial bearing.

As shown in Fig 2, the door assembly 36 is carried by a hinge 76 one part of which is secured to or is integrally formed with the front wall 18 of the cabinet 10 and the other part of which is secured to or integrally formed with the door panel 38.

Diametrically opposite the hinge, the door assembly 36 is held in its closed condition by means of a door catch 78.

The hinge 76 includes a pin (not shown) which extends through interlocking segments of the two hinge parts in manner known per se.

The length of the pin (and therefore the length of the hinge 76) and the length of the door catch each equates to approximately 50% of the diameter of the door panel 38, so as to resist bending or distortion of the door due to pressure differentials between the inside and outside of the dram 20. Although not shown pumps are mounted within the cabinet for pumping liquid such as water or water and detergent into the drum 20, pumping liquid from the drum 20, pumping air to or withdrawing air from the drum 20 to pressurise or partially evacuate the drum to assist in forcing washing liquid into the material to be washed and removing moisture therefrom during a drying cycle.

The cabinet also houses a heater (not shown) for warming some of the air to be forced into the drum and for means (not shown) for forcing air into the drum, and controls and a programmable control system for controlling washing and drying operations of the machine.

Claims

1. A washing machine comprising a cabinet containing a stationary cylindrical drum and a door for closing a circular opening in a wall of the cabinet and which when closed prevents fluid from entering or leaving the open end of the drum and when open gives access to the interior of the drum, wherein:

a) the door is hinged to the cabinet and has part of a door closing catch mechanism at a diametrically opposite position,

2. A washing machine as claimed in claim 1 wherein the window is a frusto conical protrusion from the rear of the door.

3. A washing machine as claimed in claim 1 or 2 wherein the annular sealing member around the circular opening in the cabinet is a gasket seal and the annular sealing member on the rear of the door is received in and seals to the gasket seal.

4. A washing machine as claimed in claim 3 wherein the annular sealing member on the rear of the door is in the form of a frusto conical shell, and the frusto conical wall thereof co-operates with the gasket seal.

5. A washing machine as claimed in any of claims 1 to 4 wherein in use the drum is subjected to pressures above and below ambient and the gasket seal resists fluid ingress into, and egress from, the drum.

6. A washing machine as claimed in any of claims 1 to 5 wherein the drum is resiliently supported within the cabinet to accommodate vibration as non-concentric washing loads rotate.

7. A washing machine as claimed in any of claims 1 to 6 wherein the open end of the drum is extended towards the opening in the cabinet, which in use is closed by the door, by a cylindrical bellows.

8. A washing machine as claimed in claim 7 wherein the said second annular sealing member is provided around the end of the bellows facing the door.

9. A washing machine as claimed in any of claims 1 to 8 wherein the hinge comprises a first part which is secured to or is integrally formed with the door housing, a second part which is secured to or forms part of the cabinet, and a pin which joins the two hinge parts and allows relative pivoting therebetween, wherein the length of the pin and the two hinge parts is sufficient to support the weight of the door and prevent it from distorting under pressure differentials thereacross.

10. A washing machine as claimed in claim 9 wherein the axial length of the hinge equates to 50% of the diameter of the opening in the cabinet which is closed by the door.

11. A washing machine as claimed in claim 10 wherein the door catch mechanism extends parallel to the axis of the hinge and the axial length of the catch mechanism is also of the order of 50% the diameter of the opening in the cabinet, so that the door catch mechanism also assists in resisting any distortion of the door due to pressure differentials thereacross.

12. A washing machine as claimed in any of the preceding claims wherein the door catch is electromagnetically operable an interlock prevents the door from being opened when the machine is operating.

13. A washing machine as claimed in claim 12 wherein the door catch includes a manual override device to enable the door to be opened in the event of a power failure.

14. A washing machine as claimed in any of the preceding claims in which a second drum is rotatably mounted within the stationary drum and articles to be washed are put into a basket which in use is inserted into the second drum.

15. A washing machine and door assembly therefore constructed arranged substantially as described herein and with reference to the accompanying drawing.