CA1048130A - Washing machines and controls therefor - Google Patents

Abstract

ABSTRACT

In a washing machine an electronic control circuit which includes a logic circuit providing a number of machine programmes, each programme being selected by operation of one of a plurality of momentary switches, and in which first reset means is provided to cancel the selected programme when it has been completed, and second reset means is provided to cancel the selected programme upon failure of the electrical supply to the logic circuit, a memory means being provided to prevent this latter cancellation for short term interruptions of mains electrical supply of the order of 8 seconds.

Description

- 2 ~
This invention relates to washing machines for clothes or dishes and specifically to such washing machines having an electronic programme control means.

:
At prasent one typc~! of washing ~achine normally has electro-mechanical programme control means including a timing motor which revolYes a shaft having programme cams thereon which cams are caused to effect the desired programmS~ switch~
ing. With such a control ~eans~ if there is an interruption sDf ths~ mains electrical supply during a programmSs~ then~ when ths9 supply is re-estab~shedg the programme will commence fro~
where it was interrupted unle~3 the shaft has been manually revolved during the interruption5 In ~ashing machines of the type having an electronic control means it is necessary to make special provision for interruption of electrlcal supply during a programme a~sd also to provide for what i~ to happen at the end of a programme.
It is an ob~ect of the invention to provide a control means providing a plurality of programmes and in which any selected ~' programme wlll be held where it was interrupted in the ev0nt of a short term interruption of the mains supply but which will be reset to its starting condition for switch off of the ~ mains supply or for longar term interruption3 thereof.

; According to ths~ invS~ntion we provide in a washing machine having; a plurality of electrically energised ~eans s~

3~

for performing respective furLctions of the machine; a control means comprising a logic circ:uit including a prograrnme matr-lx circuit for causing the machine to operate in accordance with any one of a plurality of programmes, and a plurality of s~itch means for selecting respective ones of said programmes; and a power supply circuit itself energised from a m~ins ~upply for energi~ing said logic c~rcuit; the improvement wherein--a. each of said switch means comprises a manuallyoperable momentary switcht b. a respective one of a plurality of stores i9 operatively connected between a respectively assQciated one of said mom~ntary switches and an input of said matrix circuit and is responsive to operation of said as~ociated switch to be changed from a disenabled condition ~` to an enabled condition to addrs~s said matrix circuit for establishing a respective one of said programmes, c. means respon~ive to the enabling of any one of said ~tores are provided to hold the remainder of said stores each in a disenabled condition, d~ first reset mean~ are provided for resetting an enabled one Q~ said stores to its disenabled condition ln response to completion of the programme selected by enabling of said store, 3c~

e. second reset ~eans are provid~d ~or resetting said enabled one of` said ~tores to its dis-enabled condition i.n response to discontinuanc~
of energisation of said logic circuit by said power supply mean~ 9 f. memory means are pro~ided for temporarily m~intaining said second reset m~an~ ln it~ non-. r~sponsive condition during discontinuance of ;. 3aid mains supply for a period not exceeding a ' predetermined time lnt~rval.

, The control means thu~ provide~ ~or resetting thestores at the end of a programme. Thus~ when reloading the machine after the completion of a programme the user will have to make a fresh programm~ ~election before the machine will start and this avoids the problem of having an i~correct ..
programme for the clothes whlch have been loaded into the . wa~hing machine~
. .
,~
Secondly~ if there i9 a failure in the electrical supply to the logic circuit the ~tores will be re~at and it w111 then be necessary for th0 user to resel~ct a programm~
ha require~; and this will 9tart all ov~r again.

:'' l`he control include~, howe~0rD a ~hort term memory means so that the store~ are not re~et Imle3s the main~
supply i9 discontinued for more than a pradetermi~ed time interval~ e.gO 8 secondsO Such a memory mea~q may b0 a ... .

.','' :: .

capacitor connected across the supply to the logic circuit~

The power supply circuit may include a battery should it be desired to provida a facil~ty to maintain the supply to the logic circuit in case of mains interruption on a longer term ba~is, i~e. ~or more than 8 seconds~ In such a case the stores will only be reset when the logic circuit supply is ef~ectively interrupt0d by failure of tha battery, discharge thereof, or switching off the machine~

. ,~

Revarting to the first of the~e rsquirements, i.e, to maintain logic circuit energisation for up to 8 seconds, the second reset means may comprise a latching relay which is latched when any stores is energised by i~itiation of a programme and drops out on a supply interruption exceeding said predetermined time lnterval and has a contact ~hich, on supply re-~stablishment, passe~ a re~et si~nal to the stores~

The memory means may comprise a capacitor connec$ed to the power supply circuit and to the second reset means, $he capacitor being charged upon connectlon o~ the power supply circuit to tha mains supply~ The second reset means may include means to sense the voltage acro~s the capacitor and which, when the voltage ~s below a predetermined value~
enables a reset signal to be passed to the stores.

:

.:
' 3~

If desired there is provided m~an~ for ensuring that, if no programme ha~ been selected, or the ~election has been cancelled by resetting the storeq, if there is any water in the washing machine it is pumped out b0fore a programme can recommence~ Thu~ there may be a le~el switch in the washi~g compartment of the machine and the control ls arranged ~o that when -the level switch sense~ that there is water in the compartment and also that no programme has ~en selected it will operate means to discharge the water from the washing compartment before enabling furth~r operatlon of the machine.

The means for performing reCpecti~e functions of the machine may include motors~ valYes~ heaters etc~ to cause the machine to e~ecute a programme.

The invention will now be described in detail by way of example with reference to the accompanying drawlngs in which~-,' ~IGURE 1 is a circuit diagram illustrating an .- electronic wa~hing machine control means conctituting a flr~t embodiment of the invention;

. ~
, . .
FIGURE 2 is a circuit detail showing a modified form of second reset means usable in the circuit of Figure 1.

:~IGURE 3 i~ a block diagram illustratlng the manner in which the logic circult is pro~ided with an electrical :, ~' .: `
,' ' supply~ and ~ IGURES 4 and 5 are diagrammatic vi~w~ in front ele~ation and section of a washing machine embodying the in~ention~

Referring first to ~igure 1~ the washing machine comprises a washing compartment 10 with which are as~ociated hot and cold water inlet val-ves 11 and 12 to control inlet of the water to the compartment. An outlet pipe from the washing compartment is indicated at 13 and contains a discharge pump 14. A level ~witch 15 projects into the wa~hing compartmentO
Although only one switch is shown there may be two such level ~witches i~ which case the switch 15 will be low level switch.

The wa~hing machine control means is intended to enable the user to select any one of a number of programmes.
Each programme is brought into operation by a manually opera-ble programms selector switch of which only two are shown ln Figure 1 at t6 and 17~ the switches being of the momentary type which are spring urged to an open positio~. The circuits a3sociated with each of the switches are similar and one such circult will be de~cribed first in relation to the swltch 16, A line 18 con~ects the swltch 16 with an AND gate 19 the output of which is connected by a line 20 to a store 21 a The store may be energised~ so that it will pa~q a signal~ by means of a signal applied along the line 20 to .its S terminal 9 3~

and may be de-energised to a non-conducting st~te by a signal applied to its R terminal. A line 22 connects the ou-tput of the store 2I to a NOR gate 23 which i~ common to all the selector circuitsJ A line 24 connects the llne 22 to the line 18 and contains an isolating diode 25.

Associated with the switch 17 in a similar manner is an AND gate 26, a store 27, a line 28 connecting the ~witch 17 to the AND gate 26, a line 29 connecting the AND gate 26 to the store 27 and a line 30 connecting the store 27 to the N~R gate 23~ A line 31 connects lines 30 and 28 and contains an isolating diode 32. The NOR gate 23 receives the outputs from all of the stores ~uch as 21 and 27 which irl turn are associat~d with respective ones of the programme selecting switche~

, ~

` An output line 33 extends from the NOR gate 23 to 'J' a matrix circuit including a programme matrix and including a read only memory~ The latter is shown diagrammatically as a number of output line~ from the stepping section 34 of the matrix, these lines being indlcated at 35, each line corres ponding to a programme step. A skip line is shown at 36, the skip line being connected to an OR gate 37 the output - of which is connected by a line 38 to the input of the :..
` stepplng section 34 of the ~atrix, ,~

A "no programme and inhibit" line 39 con~ects the line 33 to each o~ the AND gates 19 and 26 and, assuming that there are more than two programmes, to all the other similar AND gates a~sociated with the other programmes. A clock arranged to provide timing pulses is indicated a-t 40 and is con~ected to the matrix 34~ The timing pulses are preferably derived from the mains A.C. voltage applied to the washing machine~

Two programme lines are shown at 41 and 42 connected to a selection of the programme step lines 35 controlllng operation of respectively associated functional ~eans. Th2 lines 41 and 42 are connected respectiYely to the lines 22 and 30 and to reqpective inputs of the OR gate 37 and are a~sociated respectively with the switches 16 and 17~

There will be as many programme lines such as 41 and 42 as there are switches such as 16 and 17, each switch being associa-ted with~ and being operable to select, a programme line and thus a desired series of programme steps 9 performance of which i9 dependent flrstly upon sequential enabling of the lines and secondly upon selective enabling of a programme line connected thereto. Each programme line iB also connscted to the OR gate 37.

The stores 21 and 27 are reset, :iOe. de-energise~, at the end of a programme by means of a signal on a line 43 3~
._ 10 from the matrix 34. The line 43 passes to an OR gate ll4 and the output from the OR ga-te passes along the line 45 to the reset inputs R of the stores 21 and 270 The line 43 consti-tutes first reset means to reset the stores at the end o~ a programme~

The logic circuit, which includes the stores, gates and matrix circuit described, i8 shown in Figura 3 at 46 and is provided with power from a power supply circuit includlng a mains transforming and rectifylng circuit 47 controlled by ganged mains ~witches S1. To retain the logic cirouit ., activated if there should be a short term failure of the mains supply, a capacitor 52 is connected across the lines 49 to provide a short term memory, e.gO for 8 seconds. To retain . the logic circuit activated if there ~hould be a mains failure exceeding an 8 second duration7 tha power supply circuit includes a battery 48 connected across the output line 49 o~
the power supply circuit and protected by diodes 50. A switch S2 is ganged with tha switches S1 to open and close therewithO
A supply indicator light SL is connected across the line~ 49 The battery voltage is slighgly less than the transformed and rectified voltage acros3 the lines 49. The battery 48 is ; connected across the lines through a switching element 51 conn~cted to the logic circuit. When a programme is sel~cted, the battery i~ cGnnected across the lines 49 by the element 51, but, because of the voltage relation already mentioned, there is no current drain on tha battery so long as the mains is operativeO If the mains fails, the switches 51 and 52 remaining ;'', `' ' 3~D
., closed9 the battery 48 powers the loglc circuit to maintai~
its state, but no clock pulses are provided because the clock 40 is driven by the ~ains at the frequency thereof. On resumption of supply from the main~, any programme that was interrupted when th0 mains failed will pick up at the position it left off, If the logic circuit electrical supply i~
ir~terrupted by operation of the ~ains ~witches S1 then the switch S2 i~ also opened and the battery is disconnected from the logic circuit~ The battery thus powers the logic circuit only when the supply interruption i9 not caused by opening the switches S1.

Second reset means is provided to reset the stores 21, 27 etc. in the event of a supply interruption to the logic circuit, i~eD an interruption of supply to the point~
49a in Figures 1 and 3 but said reset means would be retained in the unoperated state for short term or long ter~ failures of the mains supply respectlvely by capacitors 52 and battery 48 according to requirements. One for~ of second reset means is shown in ~igure 1 in the form of a latching relay 53 having a coil 54 and nor~ally open contacts 55 and iq connected across line 49. A~ OR gate 56 is connected by lines 57 and 58 to the lines 20 and 29 respectively, and the output of the OR gate 56 is connected via a diode 56a by a line 59 to the relay 53 to bring abo~t initial operation, the relay being latched in thereafter by closure of contacts 55~ ~he relay has a further set of contacts 60, these being ~ormally closed, and being connected in a lin~e 61 itself connected to input of the OR gate 44~ to providle a reset signal through OR gate :' 44 to -terminals R of stores 21 and 27l . . .
~ An AND gate 62 has inputs rsspectively connected .; to the li~e 39 by a line 63~ to the le~el switch 15 by a line 64~and to a pump line 65 of the matrix 34 by a line 66 - which latter also connected to the input of the OR gat,e 37 The output from the AND gate 62 is co~nected by a line 67 through an OR gate 100 to the pump 140 A no~mally open cancel `. switch 101 has its output connected to the inputs of th~ OR
gates 44 and 100. Operation of the switch 101 resets the st~res such as Zl and 27 thu~ c~ncelling a~y programme which has been selected~ and also causes pumping out of any water in the containsr 15 as will be describedc , Indicator lights 68 and 69 ar~ connected to the : lines 18 and 28 respectivsly and are lit when the switch associated with the line has been operated to selsct a programme and are retained ln the lit condition by outputs fro~ llnes 24 and 31 respect~ly. Similar lights are asscciated with the other pro~ramme switches (not ~hown).

': The opsration of the circu~t thus far described will :
now be explained~ It will be asisumed that the store~ 21 and 27 are de-lanergised, i.e~ in their non~conducting state; and ,., that the relay 53 i9 de~energised but that the switches Sl .~;

.- .
, ,i . .

.:"

.:

and S2 have been clo~ed and that there is electrlcal supply to the circuit 46.

If the programme selector switch 16 1 3 pressed then a ~ig~al will pass along the line 18 to the AND gate 19. If none of the stores such a~ 21 and 27 i3 already energi3ed there will be a no-programme slgnal on the line 39 and tha AND gate 19 will have an output which will pass along the line ZO to energise the store 21. An output will then pa~s along the line 22 to the NOR gate 23, pro~iding an inverted output along the line 33 to the stepping section 34 of the matrix circuit. The light 68 will be energised by means of a signal along the line 24~ A sig~al on line 33 will also enable the clock 40 so that the pulses will be passed to the ~tepping section 34 of the matrix circuit.

The appearance of an inv~rted output o~l the line 39 inhibits all the AND gates such as 19 and 26 and thus prevents a~other programme bei.ng selected once one programme has been selected.

'';
The signal on the line 22 will select the programme : line 41, a~ld with the enabling of the clock 40, the machine will start *o wash through the programme steps of the programme ~elected as determined by the lines 35 to which the progra~me line 41 i9 connectedO Additional inputs to the matrix circuit, such as completion signal~ generated by the . .

, 3~) attainment of a predet~rmined temperature, or wa-ter le~el, are fed into the matrix 34 through the input~ to OR gate 37 along the line 38, and cause stepping of the programme lines 35 to be enabled in sequence in the known ~an~er~

The s~p line 36 i9 provided in case the stepping . section of the matri~ circuit should move from it~ "home"
:-, , position with no program~e selected, and ensures that the ,. .
stepping section returns to it~ home position at the clock frequency ready to start a programme~
, .
At the cvmpletion of a programme 9 a signal appears on the line 43 and this i9 fed to the OR gate 44 producing an output on the line 45 which resets the store 21 to restore lines 22, 24, 33 and 3g to their initial state~ so that the machine is nov ready for another programme selection.

~; A similar operation would have taken place had the .;
selector switch 17 been pressed in~tead of the selector qwitch 16, but would have involved the ~ND gate 26 and the store 27 and lines 30~ 31~ 33 and 390 Thera will be an AND gate and ~", store similarly connected :for each programme switch.

Wh,en a signal appears on the line 20 due to opera-. tio~ o~ the switch 16, the signal is fed along the line 57 ;~ to the OR gate 56, thu~ producing a sîg~al in the lina 59 .'~,' ~; to energise the relay 53 and close the contacts 55, thus ,:-:'`",-',.

~ ~5 8~3~

latching the relay in and opening the contacts 600 Should there be an interruption in the supply to the logic circuit 9 due either to a power failure exceeding 8 seconds, or opening of the switches S1 and S2 9 then the relay 53 will drop out and this wlll cause opening of the contacts 55 and closing of the contacts 60. A reset si~nal level ~aintained on line 61 will pass through the contacts 60~ both prior to operation of any of the switches such as 16, 17 and when contacts 60 close due to the power failure or opening o~ switches S1 and S2 as just mentioned. The reset signal generated will pass through the OR gate 44 to the reset line 45 thus to reset the stores 21 and 27 and all the other stores. It will thus be necessary for the user9 after a supply interruption, to reselect a new programme which will then start from the beginning.

A short ~upply interruption~ e.g. not more than 8 seconds~ will not affect the programme because of the short term memory provided by the capacitor 52. When the battary 48 is provided main3 failure of longer than 8 seconds~ while the switches S1 and S2 are closed, will be dealt with by the battery 48 holding the logic circuit in the state it is at failure and the second reset means unopera-ted. Should the battery voltage be low9 or should it not be pro~ided~
the stores will be reset a~ter 8 second~ as al~eady described~
Inter~uption of the supply by opening the switches S1 and S2 will result in resetting of the stores by closure v~ normally open contacts 60.

.;~

_ 16 It is possible for the supply failure to have taken place when the programme i9 at a state in which -there is water in the washing compartment 10 and it will therefore be de~ir able for this compartment to be emptied before the programme is restarted. If there i5 a no-programme signal on the line 3g and a signal from the level switch 15 showing that there is water in the washing compartment 9 signals will pass along the lines 63 9 64 and 66 to the AND gate 62 and this will bring about operation of the pump 14 by means of a signal pas3ing along the line 67 Op~ration o~ the pump may be terminated~ either after a predetermined ti~e d0lay, or when further senslng means~ not shown~ senses that there is virtually no water left in the wa~hing compartment. After the water has .
been discharged from the washing compartment the programme can continue. Operation of the cancel button 101 will also operate the pump 14 through the OR gate 100 a~ well as resetting the stores through the OR gate 440 ' :

The invention provides first reset means which resets the stores 21 and 27~ i~eO de-energi3e~ them~ to a ; non~conducting state at the end of a progra~me by m~ans o~
~` the signal on the line 43. Also provided is second reset means comprising the relay 53 which ensures that, aft0r ~ains supply interruption of not ~ore than 8 seconds, or longer if battery 48 is provided~ the stores are r~s0t to their non i; conductlng states thus preventing the pic~ing up of a programme at a random point, or the inadvertent use of the 3~:~

wrong programme due to it having been used the last time the machine was used.

Figure 2 shows an alternative arrangement in which the capacitor 52 is replaced by a re~istor 71 and capacitor 709 and latching relay 53 is replaced by a store 73, and in which the OR gate 56 and its as~ociated line~ 57~ 58 and ~9 are omitted.
'''' Thus ref'erring to Figure 2~ the capacitor 70 and resistor 71 are con~ected in series across the logic circuit ~upply lines 72 corresponding to lines 49 o~ Figure 1. The store 73, having set and reset inputs S and R, is connected across the capacitor and its output i3 connected to a line 74 itqelf connected to one input of an AND gate 75. The output from the AND gate 75 i9 connected by a line 76 to an OR gate 44a, the line 76 taking the place of the line ~1 in ~igure 1~ The circuit is otherwi~e as Figure 1, the gate 44a taking the place of the gate 44~ A reset signal is . . ~
applied along the line 77 to the AND gate 75 from the positive line.

The store 73 compares th0 voltaga across the capacitor 70 with the thre~hold reset voltage of the store.
When the supply 72 is first connected the signals on both the R and S inputs of the ~tore 73 are both low, as capacitor 70 charges R input is dominant and there will be a reset 3~

signal on the line 74 which~ with the positiv~ supply connected on line 77, will provide an output on -the llne 76 and thus a reset signal on the line 45a corresponding to the line 45.
When the capacitor 70 is cha:rged voltage on the S input builds up, the store 73 will be ener~ised so that there will be no output on the lines 74 and 76 and thus no reset signal on the line 45a until a mains failure of sufficient duration has occurred to discharge capacitor 70 to supply a signal at Ro '' Referring now -to Figures 4 and 59 these ~how a washing machine embodying the invention~ the washing machine comprising a cabinet 80 having a front loading door 81 and a control panel 82. The control panel carries a pl~lrality of momentary switches some of which are indicated at 83, the switches controlling the programmes and being equivalent to the ~witches 16 and 17 shown in Figure 1. Associated with each switch is an indicator light, some of which are indicated at 84~ The control panel also carries the mains switch S1, the indicator light SL and the cancel switch 101. The washing container is indicated in Figure 5 at 85 and i~
rotated by means of a motor 86 by means of a belt 87 entrained aro~ld pulle~s on the motor and the contain~r 85~

The washing machirle includes functional items such as the water inlet valves 10 and 11 shown in Figure 1~ the motor 86, if desired a heater for the water and level switches and the various functional elements of th0 washing machine, ~ e~ 30 .- 19 i.e. the motors~ valves etc. are operated in the clesired sequence :for the particular programme upon r~ceiving signals from the logic circuit as determined by the conn0ction between the programme lines such ~s 41 ancl 42 and the programme ~tep lines 35.

,::
'~,',1

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:-

1. In a washing machine having; a plurality of electrically energised means for performing respective functions of the machine; a control means comprising a logic circuit including a programme matrix circuit for causing the machine to operate in accordance with any one of a plurality of programmes, and a plurality of switch means for selecting respective ones of said programmes; and a power supply circuit itself energised from a mains supply for energising said logic circuit; the improvement wherein:-a. each of said switch means comprises a manually operable momentary switch, b. a respective one of a plurality of stores is operatively connected between a respectively associated one of said momentary switches and an input of said matrix circuit and is responsive to operation of said associated switch to be changed from a disenabled condition to an enabled condition to address said matrix circuit for establishing a respective one of said programmes, c. means responsive to the enabling of any one of said stores are provided to hold the remainder of said stores each in a disenabled condition, d. first reset means are provided for resetting an enabled one of said stores to its disenabled condition in response to completion of the programme selected by enabling of said store, e. second reset means are provided for resetting said enabled one of said stores to its disenabled condition in response to discontinuance of energisation of said logic circuit by said power supply means, f. memory means are provided for temporarily maintain-ing said second reset means in its non-responsive condition during discontinuance of said mains supply for a period not exceeding a predetermined time interval.

2. The improvement according to claim 1 wherein said memory means comprises a capacitor connected to said power supply circuit and to said second reset means in a configuration to be charged when said mains supply is applied to said power supply circuit, and to supply current to said logic circuit and to said seccond reset means to maintain the latter in its non-responsive condition over said predetermined time interval.

3. The improvement according to claim 1 wherein said power supply circuit includes;-a. first switch means for disconnecting said mains supply from said power supply circuit, b. a current source independent of said mains supply for energising said logic circuit, c. second switch means connecting said current source to said logic circuit and to said second reset means, and responsive to closure and opening of said first switch means to establish and cutoff current from said source to said logic circuit and to said second reset means whereby, after elapse of said predetermined time and during discontinuance of said mains supply only when the first said switch means are closed, said logic circuit continues to be energised from said current source and said second reset means continues to be naintained in its non-responsive condition.

4. The improvement according to claim 1 wherein said second reset means comprises:-a. a relay having normally open latching contacts connected in series with an operating element of said relay, and said power supply circuit to hold said relay operative when once operated, said relay further haivng normally closed contacts, b. means operatively connecting said normally open contacts to reset inputs of said plurality of stores to pass reset signals thereto in response to operation of said normally closed contacts.

5. The improvement according to claim 1 wherein:-a. said memory means comprises:-i. a capacitor connected to said pow er supply circuit in a configuration to be charged when said mains supply is applied to said power supply circuit, ii. means controlling the rate of discharge of said capacitor upon discontinuance of said mains supply, b. said second reset means comprises:-i. sensing means connected to said capacitor and responsive to discharge thereof to generate a reset signal, ii. means connecting said sensing means operatively with inputs of said plurality of stores when said charge on said capacitor falls to a predetermined value.