NZ215572A

NZ215572A - Automatic washing/drying machine; increased water flow through heated air condenser during washing cycle flushes out lint deposits

Info

Publication number: NZ215572A
Application number: NZ215572A
Authority: NZ
Inventors: R J Parsons; L P Didlick
Original assignee: Hotpoint Ltd
Priority date: 1985-03-25
Filing date: 1986-03-21
Publication date: 1988-04-29
Also published as: GB2172977B; GB2172977A; GB8507722D0; GB8606781D0

Description

<div class="application article clearfix" id="description"> # 215572 Priority Date(s): .. r^$.. ?i - i? N.Z. PATENT OFFICE 21 MAR 1986 RECEIVED Corr.pScte Specificstion PI'?t^STS.^ Class: .3XQLp.fr.25~/cX>, rW... '"'•'T'nV 2 9 APR 1988'''' Publication Date: P.O. Journal, No: . ....\2Grt. NEW ZEALAND No.: Date: PATENTS ACT, 1953 6% COMPLETE SPECIFICATION VOASHWG- ■^rHrrrnrsif/TRAP rccD1 ^We, HOTPOINT LIMITED, a British company of Peterborough PE2 9JB <-• England. hereby declare the invention for which Xl)(/ we pray that a patent may be granted to ttJCdC/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- - 1 - followed by page -las' - ,/ _l......,s.yv: | ©' 215572 p 0 1«. - Washing Machines This invention relates to washing machines of the kind in which a perforated drum is mounted for I rotation about a substantially horizontal axis within an outer container, and particularly to so-called J 5 combination washing machines which are arranged to ^ r—v perform a tumble drying operation following the J completion of the washing, rinsing and spin cycle of operations. Now in some combination washing machines, heated 10 air is commonly passed through the perforated drum during the tumble drying operation to remove moisture from clothes within the drum, the air, after leaving the drum, being fed past a surface cooled by the passage of a film of cold water, in order to remove moisture 15 from the air by condensation, the air then being either discharged from the machine or recirculated through the heating means and the drum. One difficulty that sometimes occurs in such combination washing machines is that particles of 20 lint tend to accumulate within the air-flow path during a drying operation, for example in a duct forming part of the condensing system. In order to avoid any appreciable degree of moisture pick-up by the circulating air during a drying operation the flow of 25 water through the condenser duct is kept to a minimum consistent with providing adequate condensation, but this has been found to be insufficient to provide satisfactory flushing of the lint particles from the duct. U 215572 -2- According, therefore, to one aspect of the invention, in a combination washing machine of the kind referred to, incorporating a condensing system 1n which heated air after leaving the perforated drum during a tumble drying operation is cooled by a flow of water, a quantity of water is fed through the condensing system via a nozzle in the uppermost region of a condenser during a washing or rinsing operation at a rate significantly greater than that at which it is fed during a drying operation being directed against a surface which tends to produce a dispersion of the water over the interior of the condenser, said condenser conveniently comprising a duct of arcuate form extending from a region near the top of the outer container to a region below the level of the axis of rotation of the perforated drum, and communicating with the interior of the container through an. opening which also provides an exit for air leaving the container during a drying operation, the air passing upwards through the duct and being cooled by the downward flow of water, which is arranged to be fed into the top of the duct. Preferably said opening is in the rear wall of the container. By this means it is possible to flush out lint particles from the condensing system more effectively than can be achieved by the flow of condensing water. If the water is fed into the condenser, the flushing operation is thereby enhanced, the most suitable rate and manner of feed of the flushing water for any particular application of the invention being readily ascertainable by trial. In combination washing machines of the kind referred to, soap or detergent, which may be in either powder or liquid form, and possibly also a fabric conditioner, are arranged to be flushed from a dispenser, in the usual way during a washing operation, by a flow of water, which passes from the dispenser into the outer container through a liquid trap in the form of a 'U'-bend, rinsing water also being arranged to be fed into the container through the trap. The latter is arranged to retain a quantity of water after the completion of the final rinsing operation in order to prevent moistucg^laden air from escaping through the dispensing system and into the room containing the washing machine during the subsequent tumblj^dj^fp^-operation. ft- v . 215572 S -3- invention a cross-connection is preferably provided between the pipes feeding the fabric conditioner, pre-wash or wash dispenser compartments and the condenser downstream of the valves. A restrictor may be fitted 5 in the or each pipe feeding the condenser, ensuring that, during rinsing, water is fed through the dispenser whilst allowing a sufficient flow through the condenser to achieve adequate flushing. In machines in which water is arranged to drain 10 from the condenser into the outer drum during the tumble drying operation, it will be seen that this drainage will also take place during a rinsing operation, and similarly during a tumble drying operation a quantity of water will also flow into the outer container from 15 the 'U'-bend when the latter is full, but in neither case is this detrimental. Thus the rate at which water is fed into the machine during a drying operation can readily be controlled so that any additional water flowing into the outer container from the 'U'-bend does not 20 contact the perforated drum but merely trickles down the inner surface of the container; this, in fact, has the advantage that it assists in the condensing action. Any water fed into the outer container during a tumble drying operation must of course be drained or 25 pumped continuously from the container. The condenser conveniently comprises a duct of arcuate form extending from a region near the top of the outer container to a region below the level of the axis of rotation of the perforated drum, and 30 communicates with the interior of the container through an opening which also provides an exit for air leaving the container during a drying operation, the air passing upwards through the duct and being cooled by the downward flow of water, which is arranged to be fed into the top 35 of the duct. Preferably said opening is in the rear wall of the container. An electrically driven blower is conveniently ' ' - ' L... ' 0 o vj> 215572 -4- arranged to feed the air around a closed path, the air, after leaving the duct, being arranged to be passed over heating means and then fed into the perforated drum through an access opening at the front 5 of the drum. Water from the condenser is preferably fed on to a gutter attached to the inner surface of the outer container, and arranged to extend slightly downwards so that water spilling from its lower end 10 spreads over the lower part of the curved surface of the container, this also providing a supplementary condensing facility. A further difficulty which-is frequently experienced with combination washing machines is that 15 the liquid trap, which is commonly formed of flexible material, tends to discharge some of its contents during the final spinning operation as a result, it is believed, to a pumping action produced by vibration, and in some cases this can be sufficient to destroy the 20 effectiveness of the trap and thereby provide a passage for the moisture-laden air. According, therefore, to another aspect of the invention in a combination washing machine of the kind referred to, incorporating a condensing system 25 in which heated air after leaving the perforated drum during a tumble drying operation is cooled by a flow of water, a proportion of the water fed into the machine during the drying operation 'is diverted into the liquid trap. 30 By this means it is ensured that any loss of water from the 'U'-bend during the final spinning operation is replenished, and the effectiveness of the liquid trap is thereby maintained. The rate of flow of water into the machine can readily be controlled to 35 provide an adequate condensing action and to ensure"" -... replenishment of the 'U'-bend. "p'V. \ 215572 -5- One combination washing machine in accordance with the invention and a modification thereof will now be described by way of example with reference to Figures 1 to 6 of the accompanying schematic 5 drawings, in which Figure 1 is a front elevation of the machine, Figures 2 and 3 represent , in diagrammatic form, a sectional side view and a plan section illustrating the drying system, 10 Figures 4 and 5 represent, also diagrammatically, a sectional view of the machine from the front and rear respectively, and Figure 6 represents a sectional yiew, similar to that of Figure 5, of the modified machine. 15 Referring to the drawings, the .combination washing and drying machine comprises a perforated clothes drum 1 mounted on a driving shaft (not shown) for rotation about a horizontal axis and within a stationary outer container 3- The outer container 3, 20 which is provided with an opening at its front end, is mounted within an enclosing casing 4 which forms part of the washing machine cabinet. The casing 4 is provided in its front wall 5 with an access opening 6 through which clothes may be loaded into or removed 25 from the perforated clothes drum 1. The access opening 6 is provided with a door 7, the periphery of which engages a flexible seal 8 when the door is closed, and seals the opening in the front of the outer container 3 and effectively closes the front of ^4 Ft Bl93S, 21 ^ r- *v o ~ &±o<j (4> -6- the perforated clothes drum 1 . The clothes drum 1 is arranged to be driven, in use of the machine, by an electric motor coupled by means of a poly-V-belt to a pulley secured to the 5 clothes drum driving shaft which extends through the rear wall 17 of the outer container 3; the driving arrangements for the drum, which can be of any convenient kind and are not relevant to the invention, have, however, been omitted from the drawings for 10 simplicity. A closed air circulating.system for the washing and drying machine comprises an electric motor 11 (Fig. 3) for rotating an impeller 12, these being mounted in a housing 13 integrally moulded with a 15 condenser 14. The condenser 14 has a duct 15 arranged between the housing 13 and an inlet to the perforated clothes drum 1 via an opening 16 in the back plate 17 of the outer container 3 as shown more clearly in Figures 4 and 5, in which the perforated drum has been 20 omitted. The opening 16 is situated on a line subtending an angle of some 20° below the centre line of the drum, and at a position near the extremity of the drum (see especially Figures 4 and 5). The condenser duct 15 is of arcuate form from its lower extremity 25 adjacent the opening 16 up to an upper region where it turns into a nearly horizontal section 18 and from where it passes through a right angle to the inlet 19 of the fan housing 13- The outlet 21 of the fan housing is connected to one end of an enclosure 22 in the form of 30 s box, secured to the upper part of the stationary drum 3, for heating air passing through the system. Two sheathed heating elements of close-wound spiral form, and indicated diagrammatically at 23 in Figures 2 and 3; are mounted within the enclosure 22, connections (not 35 shown) being provided for enabling the elements connected to a part of the electrical circuit of the washing and drying machine. Air passing through th^* I \ 3 2 1 5 57 0 box can be heated by both elements or by a reduced output for example, one element only. At its front (exit) end the heater enclosure 22 is provided with an outlet 24 which is connected to a 5 region 25 of the stationary outer container 3 formed by an outwardly directed protruberance integral with the container, the region being closed off to the container by a plate 26 so as to form a channel 27. An injector nozzle 28 is connected to the lower end of 10 the channel and has its open end directed, at a downward angle of some 30° from the horizontal, so as to direct heated air through the front opening of the clothes drum 1 . A cooling water inlet nozzle 29 for the condenser 15 is mounted at the upper end of the arcuate portion of the condenser duct 15 so that water emitted from the nozzle passes over and down the inner surface 30 of the arcuate portion and in so doing provides a continuous flow of cooling water for the condenser 14 during a drying 20 operation. A solenoid-operated valve 35 controls the flow of water to the condenser, and also provides a restriction which limits the rate at which it is fed into the condenser during the drying operation to a relatively low value. 25 A deflector 31 adjacent the inlet nozzle 29 directs the water towards a region of the inner curved surface of the condenser duct, in this case adjacent the rear wall of the duct, thereby restricting the spread of water so as to produce a smooth unbroken film, for 30 reducing the possibility of droplets of water being picked up by the air flow, as could be the case if the water were allowed to disperse over the entire surface of the duct. In addition the film of water is shielded to a degree from the effect of the flow of air, tending 35 to disperse the water flow, by a first baffle 32 extending along the duct 15 as shown and a second baffle 33 extending over the lower lip of a V-shaped spout 34 which ■ jgf -• -8- 215572 forms part of the opening 16 and by which the water is fed into the outer container 3. The combined effect of the deflector 31 and baffles 32, 33 permits the rate of airflow to be increased to some extent without moisture pick-up, leading to a more efficient drying, as described in New Zealand Patent Specification No. 215573. After passing through the condenser 14 the water is fed by the 'V'-shaped spout 34 into a gutter 36 fixed to the inside wall of the outer container 3- The gutter 36 is arranged at a downward angle such that water spilling from its lower end 37 spreads over the lower curved surface 38 of one side of the container 3, and subsequently flows into an outlet 39 at the bottom of the container which also serves as the outlet for wash liquor during a wash cycle of the machine. An extraction pump 41 (Fig. 2) is provided together with a filter 42, the water and wash liquor being discharged via a drain pipe 43- The water flowing from the condenser 14 over a lower part of the outer container 3 thus provides a supplementary condensing facility. The cycles of automatic operation of the machine are controlled by two timers mounted to the rear of a control panel 44 and each having individual control knobs 45 and 46 for manual adjustment of the timer settings. One timer is arranged to control the washing, rinsing and spin-drying operation while the other timer is arranged to control the tumble drying operation. The wash function timer includes the facility of a pulsed spin sequence operation to be described in more detail, a facility usually provided by a third timer. A series of push buttons 47 control various operations concerned with the wash function such as gentle action and rinse hold. Also mountedV^n -the control panel is a drawer-type dispenser 48 for enabling detergent, soap powder or a fabric conditioner to.twC\' introduced into the machine during the wash ' - / ^ P1 -9- cycle. The outlet 49 from the dispenser 48 is connected to one end of a convoluted hose 50 which has its other end 51 opening into an upper part of the stationary container 3- The hose is provided with a 5 'U'-bend 52 which forms a water trap for preventing the escape of circulating air when the machine is in a drying cycle. It has been found, however, in combination washing machines as constructed hitherto that, during 10 the final spinning operation water tends to be discharged from the 'U'-bend due, it is believed, to a pumping action resulting from vibration, and this can occur to an extent that it no longer forms a barrier to moisture-laden air which can escape through the 15 dispenser and out of the machine during the drying operation. This is clearly a disadvantage and, in accordance with the second aspect of the invention a connection 54 (Figure 5) is made between the pipe 55 feeding water into the condenser 14, and the pipe 56 20 which feeds water through the fabric conditioner compartment of the dispenser 48 at the appropriate times during the rinsing/drying programme under the control of the valves 35 and 40. At the same time some of the water admitted 25 into the pipe 55 by the valve 35 is diverted into the pipe 54 and feeds into the hose 50 via the (now empty) dispenser 48, so as to replenish or maintain the level vLv of water within the 'U'-bend 52. When the 'U'-bend 52 is filled some of the water will overflow into the 30 outer container 3 through the hose outlet 51, where it will trickle down the wall of the container thereby assisting in condensing moisture-laden air. O/ In addition when water is fed into the container 3 through the dispenser 48 during the rinsing eye' 35 some of the water will be diverted through the connection 54 and a restriction 57 into the conden and from there into the outer container 3, the 2155 10 -&5>v- restriction ensuring sufficient back-pressure to cause the majority of the water to pass through the dispenser. However the rate of flow of water through 5 the condenser 14 during the rinsing cycle is arranged to be considerably greater than that which occurs during a drying operation, and is such that after passing through the nozzle 29 and striking the deflector 31 it impinges against the rear wall of 10 the condenser 14 with sufficient force to cause it to disperse over the interior of the condenser, where it runs down and flushes lint from the condenser walls into the container 3, and then through the drain outlet 39- 2155 U In operation of the washing and drying machine the machine is loaded with clothes and detergents or soap powder and fabric conditioner are introduced according to the required wash programme. Once the machine has been switched on a series of washing, rinsing and spinning operations occur, in accordance with the programme set. In a combination machine it is necessary to ensure as far as possible that the clothes, at the end of a wash function and before 10 being dried, are not left clinging to the walls of the clothes drum thus preventing them from falling to the lower part of the drum so allowing a flow of hot air through the clothes. To this end a pulsed spin sequence, which consists of a series of operations 15 viz., distribute - the clothes drum being rotated at some 85 revs/min; slow spin at some 500 revs/min; pause; distribute; pause; distribute; and slow spin, occurs, the sequence being repeated for some settings of the wash programme, e.g. cottons. This operation 20 is followed by a final spin sequence at a speed, and for a duration, according to the wash programme setting, the sequence ending with a short period of reverse tumble, i.e. the drum being rotated at a low speed in one direction and then after a pause, in the 25 other direction. Although this pulsed spin sequence is primarily to ensure as far as possible that no clothes are left clinging to the walls of the drum when the drying programme commences, its function is also of use if the user wishes to terminate the 30 washing/spin drying operation at the end of the pulsed spin sequence. In such an event the clothes are much easier to remove from the drum. Normally the machine would be used for a washing, spin drying and tumble drying operation, the tumble drying following 35 immediately after the pulsed spin sequence, the drying performance being such that it is not necessary to remove any clothes from the drum before continuing with 5 mis I; 12. I ^ >1 215572 | the tumble drying operation. f For tumble drying the clothes drum 1 is rotated in each direction at a speed of around 50 - 55 revs/ min. The heating elements 23 are energised from the 5 mains supply via suitable controls (not shown), two heat settings being available, these being obtainable by use of both elements, operating together, or one element (7" only* as required. Two thermostats (not shown) both situated in the air outlet 24 from the heater enclosure 22 x 10 are operable to control the heating elements 23 one at a high circulating air temperature in conjunction ^ with full heat output, both heaters being energised and the other at a lower circulating air temperature with only one heating element energised. A separately 15 mounted over-temperature safety cut-out (not shown) which is positioned between the elements 23 in the heater enclosure acts in the event of failure of the thermostats or some other fault causing an increase in the air temperature. The solenoid valve 35 is 20 energised during the drying cycle so as continuously to admit cold water which passes through the inlet nozzle 29 and down one side of the inner curved surface of the duct 15 for condensing moisture from the air circulating through the outer container 3 and through the duct as 25 previously explained. The electric motor-driven pump 41 is energised continously during the drying cycle so as to extract the water which has been used to condense moisture out of the circulating air. 30 The motor 11 driving the impeller 12 is also energised throughout the drying cycle, thereby providing a flow of circulating air which is directed over the heating elements 23, where it is heated, through the channel 27, into the injector 28, into 35 the clothes drum 1 and onto clothes tumbling in the drum. Moisture is taken up from the clothes and the moisture-laden air then passes through the perforations l m -13- 215572 in the wall of the"clothes drum 1 into the outer container 3 in the direction of the opening 16 and in so doing has some of its moisture condensed by the water flowing down the surface of the container. 5 The air then passes into the condenser 14 where the water flowing down its curved surface condenses further moisture. Since the air circulating system constitutes essentially a closed circuit the air continues along its path, through the heater enclosure 22 and into 10 the clothes drum again. This operation continues "as lon£ as required, according to the control setting selected by the user which, in conjunction with the thermostat setting determines the duration of the tumble drying sequence. 15 It is arranged for the sequence to include, as a final operation a period of tumble drying without heat so as to cool the clothes which have been dried, thereby minimising creasing of the clothes. During drying the clothes are reverse tumbled i.e. the drum is rotated 20 in one direction and then, after a short period of time in the other direction. A typical speed of rotation of the drum for tumble drying is 50 to 55 revs/min. The modified machine, illustrated diagrammatically in Figure 6, is similar to that already described except 25 that an additional nozzle 58 is connected to the upper part of the condenser 14, and is arranged to be fed with water during a rinsing cycle, conveniently from the pre-wash compartment water valve 59 via a suitably arranged cross-connection pipe as at 60, so that the 30 flow of water through the condenser can be further increased by the jet issuing from the nozzle 58, the resultant water flow picking up any entrained lint as it flows down the condenser. </div>

Claims

<div class="application article clearfix printTableText" id="claims"> r--•"'-r-'v 215572 -14- What we claim is: —

1. A combination washing machine of the kind referred to incorporating a condensing system in which heated air after leaving the perforated drum during a tumble drying operation is cooled by a flow of water, wherein a quantity of water is fed through the condensing system via a nozzle in the uppermost region of a condenser during a washing or rinsing operation at a rate significantly greater than that at which it is fed during a drying operation being directed against a surface which tends to produce a dispersion of the water over the interior of the condenser and wherein the condensing system includes a duct of arcuate form extending from a region near the top of an outer container to a region below the level of the axis of rotation of the perforated drum, communicating with the interior of the container through an opening which also provides an exit for air leaving the container during a drying operation.

2. A combination washing machine according to Claim 1 incorporating individual solenoid-operated valves for controlling the flow of water through compartments of the dispenser and through the condensing system from a common supply, wherein a cross-connection is provided between the pipes feeding the fabric conditioner, prewash or wash dispenser compartments and the condenser downstream of the valves, the or each pipe to the condenser including a restrictor such that during rinsing, water is fed through the dispenser whilst allowing a sufficient flow through the condenser to achieve adequate flushing.

3. A combination washing machine according to any preceding claim wherein said opening is in the rear wall of the container.

4. A combination washing machine according to any preceding claim including an electrically driven blower arranged to feed the air around a closed path, and heating means located in said path, at a position between said duct and means arranged to direct the flow of air into the perforated drum. ^ "

/,

i >

* J i,.

-15-

5. A combination washing machine according to Claim 4 wherein the means for directing the flow of air into the perforated drum comprises a nozzle disposed so as to direct the air into the drum through an opening at the front of the drum.

claim in which the outer container incorporates a gutter attached to its inner surface and on to which water is arranged to be fed by the condensing means, the gutter being inclined slightly from the horizontal and so positioned that the water spilling from its lower end spreads over the adjacent part of the lower surface of the container.

7. A combination washing machine according to any preceding claim, in which soap or detergent is arranged to be flushed from a dispenser into the outer container, during a washing operation via a liquid trap and which incorporates a condensing system in which heated air after leaving the perforated drum during a tumble drying operation is cooled by a flow of water, wherein a proportion of the water fed into the machine during the drying operation is diverted into the liquid trap.

8. A combination washing machine substantially as shown in and as hereinbefore described with reference to Figures 1 to 5 of the accompanying drawings, or as modified substantially as shown in and as hereinbefore described with reference to Figure 6 of the accompanying

6.

A combination washing machine according to any preceding drawings.

Ms/their authorised k I A SON

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