GB2181222A

GB2181222A - Machine for washing and drying domestic laundry

Info

Publication number: GB2181222A
Application number: GB08524256A
Authority: GB
Inventors: Michael Paul Denton
Original assignee: Philips Electronic and Associated Industries Ltd
Current assignee: Philips Electronics UK Ltd
Priority date: 1985-10-02
Filing date: 1985-10-02
Publication date: 1987-04-15
Also published as: GB2181222B; GB8524256D0

Abstract

A machine for washing and drying domestic laundry comprises a cabinet (3) containing a stationary cylindrical tank (1) for holding washing liquor and a rotatable perforated drum (2) within the tank in which the laundry is washed and subsequently dried. A detergent distributor (38) is arranged above the tank. For drying the laundry a stream of hot air produced by a high-speed fan (23) and a heater (24) is discharged into the drum through the front of the tank from a duct (25) which extends from the heater across the top of the tank through the narrow space between the tank and the detergent distributor and down the front of the tank between the tank and the front wall of the cabinet. The duct (25) has a flattened shape with an elongate cross-section and is made of a heat-resistant elastometric material, for example, a silicone rubber, so as to be capable of absorbing any shocks caused by vibratory contact between the tank and the duct as the drum accelerates at the beginning of the spinning operation. <IMAGE>

Description

SPECIFICATION Machine for washing and drying domestic laundry This invention relates to a machine for washing and drying domestic laundry, comprising a cabinet containing a stationarytankfor holding washing liquor, a perforated drum withinthetankfor holding laundry to be washed and subsequently dried in the drum, the drum being rotatable inside the tank about a hori zontal axis, a detergent distributor located above the tank, a fan and a heater for generating a stream of hot airfordryingthe laundry, and a ductforconducting the hot airfrom the heater into the drum.

Due to the presence of the tank and various other components which are involved in the washing oper ation,theinteriorofawashing and drying machine tends to be somewhat congested and there is a pro blem in finding space to accommodate the duct through which the hot air is conducted from the heater into the drum in the drying operation. It is an ob ject of the invention to provide a solution to this pro blem.

According to the invention there is provided a machine for washing and drying domestic laundry, comprising a cabinet containing a stationarytankfor holding washing liquor, a perforated drum within the tankforholding laundrytobewashedandsubsequ- ently dried in the drum, the drum being rotatable insidethetankabouta horizontal axis,a detergentdistributor located above the tank, a fan and a heaterfor generating a stream of hot air for drying the laundry, and a duct for conducting the hotairfrom the heater into the drum, characterised in that this duct is made of an elastomeric material and extends across the top of the tank between the tank and the detergent distributor and down the front of the tank between the tank and the front wall ofthecabinettodischarge into the drum through the front of the tank, at least the portion ofthe ductwhich extends between the tank and the detergent distributor having a flattened shape with an elongate cross-section.

Between the detergent distributor and the tank a clearance is required to allowforthe vibration ofthe tank as the drum accelerates at the beginning ofthe spinning operation, and in the present invention this narrow space is utilised to accommodate the portion of the hot-air duct which extends across the top ofthe tank. This is made possible by the use of an elas tomericmaterialfortheductandtheflattenedshape ofthe duct, since the resulting flexibility ofthewalls ofthe duct allows them to absorb any shocks caused by vibratory contact between the tank and the duct.

An embodiment of the invention in which the front walls ofthe cabinet, the tank and the drum are formed with aligned openings through which laundry can be loaded into the drum, and a flexible an nular seal extends between the front walls ofthe cab- inetandthetankand is fixed to thesewallsaround the openings therein, is characterised in that the hotair duct is connected at its discharge end to an aperture in the wall oftheseal so asto discharge into the drum through the aperture and through the openings in thefrontwalls ofthetankand the drum.This arrangement avoids any need to interfere with the constructionofthetankorthedrum.

A discharge nozzle is preferably provided at the discharge end ofthe hot-airductto directthe hotair stream from the duct into the drum, the nozzle having a discharge aperture which faces towards the open ing in the front wall ofthedrum.

Asimplemethod ofconnectingthehot-airductto the aperture in the seal is provided in an embodiment ofthe invention which is characterised in that the portion of the hot-air duct which extends down the front of the tank also has a flattened shape with an elongate cross-section, and in that the aperture in the seal has an elongate shape corresponding to that of the cross-section of the hot-air duct at the discharge end thereof and extends in the circumferential direction oftheseal and is surrounded byawallwhich projects from the outer side of the seal and over which the discharge end of the duct fits.

One embodiment of the invention is characterised in thatthewall which surrounds the aperture inthe seal issupported internallybya rigidsleevewhich has an elongate cross-section corresponding to the shape of the aperture in the seal and which also forms said discharge nozzle, the sleeve having a wall portion which projects from the inner side of the seal in a direction towards the opening in thefrontwall of the drum to form the discharge aperture ofthe nozzle.

An embodiment ofthe invention will now be described by way of example with reference to the accompanying drawings, in which Figure 1 is a diagrammatic part-sectional side elevation of a washing and drying machine embodying the invention, the cabinet of the machine, with the exception of the front wall, being omitted for the sake of clarity, Figure2 is a diagrammatic rear elevation of the machine shown in Figure 1,withthewholeofthe cabinet omitted, Figure 3 is a detailed plan view of the interiorofthe machine shown in Figures 1 and 2, Figure 4 is a detailed sectional front elevation of the upper part of the machine shown in Figures 1 and 2, the section being taken on the line IV-IV in Figure 3, FigureS is a fragmentary sectional view taken on the lineV-V in Figure4and drawn to a largerscale, Figure 6is a plan view ofthe hot-air duct ofthe machine shown in Figures 1 to 5, Figure 7is a longitudinal sectional view ofthe duct taken on the line VII-VII in Figure 6, and Figure 8 is an end view of the duct looking in the direction ofthe arrow VIII in Figure 6.

Thewashing and drying machine shown diagrammatically in Figures 1 and 2 comprises a stationary tank 1 of cylindrical form for holding washing liquor and within the tank a rotatable perforated drum 2 for holding the laundry to be washed and dried.Thetankl issuspended in a cabinet, of which thefrontwall is shown at3 in Figure 1.Thetankis arranged with its axis disposed horizontally, and the drum isrotatablysupportedinthetankcoaxially therewith by a shaft4which projects from the rear end wall 5 ofthe drum and isjournalled in a bearing (not shown) in the rear end wall 6 ofthetank.Outside the tank the shaft 4 receives drive from an electric motor (not shown) by which the drum 2 can be rotated at low speed in alternate directions during the washing and tumble-drying operations and at high speed in one direction only during the spinning operation.

The drum 2 has perforations 7 (Figure 1) in its cylin drical wall 8 and a largecircularcentral opening 9 in its front end wall 10 through which the laundry can be loaded into the drum.Thetank 1 has a similaropening 11 in its front end wall 12 and a corresponding opening is provided in the front wall 3 of the cabinet, the three openings being coaxial with one another.A flexibleannularseal 14, for example, a rubber bellows seal, is fixed to the front end wall 12 ofthe tank 1 around the opening 11 therein and to the front wall 3 ofthe cabinet around the corresponding opening inthiswall. For closing this opening a hinged porthole door 15 is provided on the front wall of the cabinet,the door being arranged to seat in a water- and air-tight manner on a rim of the seal 14 atthe front edge of the seal, and the construction of this seal and the door 15 being such as to leave an annularspace 16 between the seal 14and a transparent portion 17 of the door which has a frusto-conical shape and protrudes into the openings 11 and 9 in the front of the tank 1 and the drum 2.

In the bottom of the tank 1 is an outlet 18through which the dirtywashing liquor and rinsing water is removedfromthetankbya pump 19.Thewaterexpelled from the laundry during the spinning operation is also pumped from the tank through the outlet 18.A pipe 20 leads awayfrom this outletand has a branch 21 which is connected to the inlet of the pump 19. A drainage pipe 22 is connected to the outlet of the pump.

Following the spinning operation the laundry is tumble-dried in the drum 2 by passing a stream of hot air over the laundry while the drum is rotated at low speed in alternate directions. The stream of hot air is produced by a high-speed fan 23 and an electric heater 24. Hot airfrom the heater flows into the drum 2 through a duct 25 which passes over the top ofthe tank1 and down thefrontofthetankto discharge intotheinteriorofthedrum 2through an aperture 26 in the wall ofthe bellows seal 14,thespace 16 between the seal 14 and the protruding portion 17 ofthe door 15, and the openings 11 and 9 inthefrontwalls ofthetankand the drum.The hotair passes overthe laundry in the drum 2 to extract moisture therefrom and then flows through the perforations 7 in the cylindrical wall 8 of the drum into the space between this wall and the surrounding wall of the tank 1. The moist air leaves this space via the outlet 18 in the bottom ofthetank and the pipe 20, which serves as a ductforconductingthe moist air to a condenser 27.

Alternatively, the pipe 20 can be arranged to discharge the moist airto atmosphere externally of the machine, preferablythrough a lint filter and if desired through an extensible hose.

The condenser 27 comprises a container 28 which is divided internally into upper and lower chambers 29 and 30 respectively by a horizontal partition 31 which ends some distance from one wall of the con tainerto leave an opening 32 through which the chambers communicate with one another. The pipe 20 opens into the lower chamber30through the opposite wall of the container 28so that the moist air flowing from the pipe 20 is constrained to flow over the surface of a quantity of cooling water 33 in the bottom ofthe container 28.The water vapour in the air is condensed by this cooling water and precipitated from the air stream, which then flows through the opening 32 into the upper chamber 29 of the container, whence it is conducted by a duct 34 to the inlet ofthefan23.Thecontainer28hasa large volume in order to reduce the velocity of the airflow overthe cooling water 33. This water is fed into the container during the drying operation through a valvecontrolled inlet pipe 35 and leaves the container through an outlet pipe 36. One end of this pipe projects up into the lower chamber 30 through the bottom of the container; the other end is connected to the branch pipe 21 which connects the pipe 20to the pump 19.The depth ofthe cooling waterinthe chamber 30 is determined by the heig htto which the end ofthe pipe 36 projects into the chamber. The container should, of course, be mounted well above the level to which the tank 1 is filled with waterforthe washing operation in order to avoid flooding the container.

The condenser may have the construction described in the specification of the Applicants' co-pending United Kingdom Patent Application No (Applicants' reference: PHB33214).

The fan 23 is driven at very high speed, for ex- ample, 7,000 r.p.m., in orderto deliver air at high pressure and velocity. The air pressure at the fan outlet may be within the range 4cm to 8 cm ofwater.

With a high airpressuretheairducts mayhavea small cross-sectional area. This is of particular benefit in the case of the hot-air duct 25 which extends from the heater 24 across the top of the tank 1, since the interior of a washing machine tends to be part icularly congested in this region. As can be seen from Figures 3 and 4, in the machine shown in the drawings the space above the tank is largely occupied by a vibration-damping mass 37, for example, a concrete block, which is secured to the tank, and a detergent drawer 38 which dispenses detergent etc.

for the washing operation. A good clearance is nee ded between the detergent drawer and the top ofthe tank 1 toallowfortheamplitudeofvibrationofthe resiliently suspended tank when the speed of the drum passes through the resonant frequency at the beginning of the spinning operation, and this clearance is utilised to accommodate the portion 39 ofthe hot-air duct 25 which extends across the top ofthe tank 1. This portion and the portion 40 which extends down the front of the tank have a flattened shape with an elongate cross-section, the two flat major walls of the portion 39 being stiffened in the lateral direction by ribs 41. The duct has a corrugated neck portion 42 of circular cross-section which is connected to an outlet duct 43 from the heater 24, the inlet of which is connected to the outlet ofthefan 23 at 44. Between the neck portion 42 and the portion 39 the duct 25 has a portion 45 in which the cross-section of the duct gradually changes from a circularto an elongate shape. At its discharge end the duct 25 is connected to the aperture 26 in the wall ofthe bellows seal 14 which extends between the front end wall 12 ofthe tank 1 and the frontwall 3 ofthe cabinet. As shown in Figures 4 and 5, this aperture is of elongate shape to match the cross-section of the portion 40 of the duct 25 and extends in the circumferential direction of the seal 14.The aperture 26 is surrounded byan upstanding wall 46which projects from the outer side ofthe seal 14 and over which fits the end of the duct portion 40. The wall 46 is supported internally by a rigid sleeve 47 which is made of a plastics material and which has an elongate cross-section corresponding to the shape of the aperture 26. The sleeve 47 is formed with outwardly directed flanges 48 which en gage overthe edges of the wall 46 to secure the sleeve in the aperture 26, and a stiffening web 49 is formed across the middle of the sleeve.The sleeve 47 also forms a discharge nozzleforthe duct 25, for which purpose the sleeve has a wall portion 50 which projects from the inner side of the seal 14 and curves round in a rearward direction to form a rearwardly facing discharge aperture 51 which directs the hot air stream from the duct 25 towards the central opening 9 (Figure 1 ) in the front wall of the drum 2. Due to this and to the high velocity of the air strea m, very little hot air escapes into the gap between the front walls of the tank and the drum and by-passes the interior of the drum. To prevent small items of laundry entering this gap, an annular rim (notshown) is provided on the seal 14.

The duct 25 is made of a heat-resistant elastomeric material, for example, silicone rubber, which allows itto be routed through the narrow space between the detergent dispenser 38 and the tank 1. Shocks caused by contact between the duct and the tank as the latter vibrates during acceleration of the drum to its spin speed are absorbed by deformation of the flexible walls ofthe duct. The elastomeric material andflattened shape of the duct 25 allow the duct to expand underthe pressure ofthe air when the fan comes into operation and to collapse when the fan stops.

The present invention can be applied to advantage inthewashing and drying machine which forms the subject of the Applicants' co-pending United Kingdom Patent Application No (Applicants' reference: PHB33213).

Claims

1. Amachineforwashing and drying domestic laundry, comprising a cabinet containing a stationarytankfor holding washing liquor, a perforated drum withinthetankfor holding laundryto be washed and subsequently dried in the drum,the drum being rotatable inside the tank about a horizontal axis, a detergent distributor located above the tank, a fan and a heaterfor generating a stream of hot airfordryingthe laundry, and aductforconducting the hot airfrom the heater into the drum, char acterisedinthatthisductismadeofanelastomeric material and extends across the top of the tank between the tank and the detergent distributor and down the front of the tank between the tank and the frontwall of the cabinet to discharge into the drum through the front of the tank, at least the portion of the ductwhich extends betweenthetankandthedet- ergent distributor having a flattened shape with an elongate cross-section.

2. Awashing and drying machine as claimed in Claim 1 and in which the front walls of the cabinet, the tank and the drum are formed with aligned openingsthrough which laundry can be loaded into the drum, and a flexible annular seal extends between the front walls of the cabinet and the tank and is fixed to these walls around the openings therein, characterised in that the hot-air duct is connected at its discharge end to an aperture in the wall of the seal so as to discharge into the drum through the aperture andthroughtheopeningsinthefrontwallsofthe tank and the drum.

3. Awashing and drying machine as claimed in Claim 2, characterised in that a discharge nozzle is provided at the discharge end of the hot-air duct, the nozzle having a discharge aperture which faces tow- ardsthe opening in the front wall ofthedrum.

4. A washing and drying machine as claimed in Claim 2 or3, characterised in that the portion ofthe hot-air duct which extends down the front of the tank also has a flattened shape with an elongate crosssection, and in that the aperture in the seal has an elongate shape corresponding to that of the crosssection of the hot-air duct at the discharge end thereof and extends in the circumferential direction oftheseal and is surrounded byawallwhich projects from the outer side of the seal and over which the discharge end ofthe duct fits.

5. Awashing and drying machine as claimed in Claims 3 and 4, characterised in that the wall which surrounds the aperture in the seal is supported internally by a rigid sleeve which has an elongate crosssection corresponding to the shape of the aperture in the seal and which also forms said discharge nozzle, the sleeve having a wall portion which projects from the inner side of the seal in a direction towards the opening inthefrontwall ofthe drum to form thedischarge aperture ofthe nozzle.

6. A washing and drying machine as claimed in any of the preceding claims and substantially as herein described with reference to the accompanying drawings.