GB2095705A - Clothes washing machine drive - Google Patents

Abstract

A drive for a clothes washing machine to give agitating and spin modes uses a reversible motor 15 connected through a speed reducing transmission means to an agitator 7 so that, in the agitating mode, cyclic reversing of the motor order control of an electronic circuit causes cyclic reversal of rotation of the agitator and, in the spin mode, rotation of the motor 15 in one direction causes lost motion in a lost motion device 20, 21, 22 between the agitator 7 and a spin bowl 2 to be taken up and the bowl is then spun to remove water from clothes in the bowl. The lost motion device between a pulley 12, on the agitator spindle 8, and the shaft 3, on which the bowl 2 is mounted, comprises a pin 20 carrying a rubber buffer 21 which "engages" an arm 22 on the shaft 3 so that, in the agitating mode, the pin 20 can rotate close to one revolution without moving the arm 22 but, in the spin mode, the pin 20 carries the arm 22 and thus the bowl 2 around with the shaft 8. The lost motion arrangement can be repeated as desired for agitation through more than one revolution. <IMAGE>

Description

SPECIFICATION Clothes washing machine drive This invention relates to methods of and/or apparatus for actuating clothes washing machines and/or clothes washing machines including such means and has been devised for use in clothes washing machines of the agitator type, that is to say the type in which a rotatable spinning bowl is provided in a container and in which bowl is mounted an agitator, the agitator being in use, in an agitating phase, rotated over a range of rotatory movement first in one direction and then in the opposite direction, and in a spin phase said bowl is continuously rotated in one direction for a period of time.

It is an object of the present invention to provide methods of and/or apparatus for actuating clothes washing machines and/or clothes washing machines including such actuating apparatus which will at least provide the public with a useful choice.

Accordingly in one aspect the invention consists in a method of actuating a clothes washing machine of the type described, said method including the steps of, in the agitating phase using an electric motor connected to said agitator through a speed reducing transmission to rotate first in one direction and then in the other so that said agitator in turn is rotated over angular rotations in each direction and in said spin phase causing said motor to be connected to said bowl and to rotate the latter continuously in one direction at a high speed.

In a further aspect the invention consists in apparatus for actuating a clothes washing machine, said means comprising an agitator shaft, an agitator mounted on said shaft, a hollow spin shaft coaxial with said agitator shaft, a spinning bowl mounted on said spin shaft and in which said agitator is mounted, an electric motor having a drive shaft, a speed reducing transmission means connecting said drive shaft to said agitator shaft so that rotation of said driving shaft in one direction or the other causes rotation of said agitator shaft in the same sense as the driving shaft, a lost motion device between said agitator shaft and said spin shaft permitting said agitator shaft to rotate in either direction without causing material rotation of said spin shaft and electric supply and control means supplying said motor with current so that in an agitating phase, said motor is rotated cyclically first in one direction then in the other to cause said agitator to oscillate without causing said bowl to be moved materially from a stationary position, and in a spin phase causing said motor to rotate continuously so that free play in said last rotation device is taken up and said bowl caused to spin at spinning speed, said electric supply and control means controlling the energy supplied to said motor so that the spinning speed is at least ten times the maximum agitating speed of said motor.

In a still further aspect the invention consists in a clothes washing machine which includes apparatus for actuating the same when constructed and arranged according to the preceding paragraphs.

To those skilled in the art at which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims.

The disclosures and the descriptions herein are purely illustrative and it is not our intention to limit the scope of the invention by those disclosures and descriptions, or otherwise, than by the terms of the appended claims.

One preferred form of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a vertical partly diagrammatic sectional elevation of a clothes washing machine of the type described incorporating the invention; Figure 1 A is a scrap view of an alternative lost motion device; Figure 2 is a scrap plan view on the line Il-Il, figure 1, and Figure 3 is an electrical diagram of electric supply to and control of a motor forming part of the clothes washing machine of figure 1.

Referring to the drawings, a clothes washing machine 1 of the vertical axis top loading type is shown diagrammatically and is provided with an outer container (not shown) and an inner clothes basket or spinning bowl 2 which is perforated in the known way. This bowl is mounted on a spin shaft 3 running on bearings 4 and 5 so as to be freely rotatable. An independently rotatable agitator 7 is mounted on a spindle 8 coaxially with the member 3. The spindle 8 is driven through a collet 9 mounted in a conically apertured member l0drivenbyaboltll,bypulleyl2,abeltl3, and a further pulley 14 mounted on the shaft 15 of an electric motor 16. The speed reduction is in the range 8 :1 to 20:1 preferably 14:1 or to suit the motor characteristics.The electric motor is for example a Thomson Brandt motor type 19/70/45 which is a permanent magnet DC motor which will operate over a wide range of speeds for example between close to zero and 17000 revolutions per minute.

A lost motion coupling means is provided between the pulley 12 and the spin shaft 3 and thus the bowl 2 comprising for example a pin 20 arranged parallel to, but displaced a distance from the longitudinal axis of the spindle 8. The pin 20 preferably carries a resiiiently flexible e.g. rubber buffer 21 on it.

An arm 22 is fixed e.g. by a U bolt 23 to the shaft 3 with the radius of the arm 22 greater than the distance of arm 22 from the centre of the shaft 3. This arrangement is such that in an agitating mode the pin 20 can rotate close to 27r radians without moving the arm 22 but in a spin mode, the buffe'r 21 on pin 20 "engages" the arm 22 and carries that arm and consequently the spinning bowl around with the shaft 8 when the motor 15 is rotated continuously as will be described further shortly.

It it is required to agitate the agitator over a greater range of movement then 27r radians, the arrangement of figure 1A can be used in which pin 21 engages an intermediate arm 60 and arm 22 carries a further pin 61. The arm 60 is free on the hollow shaft and thus up to 47r radians of movement of pin 20 can result without material movement of arm 22. This lost motion arrangement can be repeated as desired.

The agitator 7, bowl 2 and associated container are resiliently mounted in any convenient way e.g.

as described in our New Zeaiand patent specification No. 194730, in a cabinet such as that shown in our copending New Zealand patent specification No. 189708 and to assist in counterbalancing out of balance clothes during spinning, an annular tube 24 is provided partially filled with a liquid and having transverse baffles (not shown) to limit transfer of the liquid.

Additionally a plurality preferably two balance weights 59 are pivotally mounted on the spin shaft 8 and these weights in use take up positions to reduce imbalance.

As is well known the bowl is rotatable at high speed, usually over 1000 RPM for extracting fluid from the clothes (i.e. spin drying) and the agitator cyclically reversible for clothes washing. Since it is desirable that the rotation of the bowl be braked if the lid is opened, if mains power is switched off or lost in fault conditions, the present invention in the preferred form provides means of converting the kinetic energy of moving parts into electrical energy and absorbing that energy preferably by use of a resistor i.e. electrical braking characterised in that means are provided to control the braking current at specific RPM rpm to designated values which may be functions of RPM.The agitator in use rotates to and fro preferably through less than 27r radians through a greater range of motion is possible to cause washing of the clothes and bowl rotation can be caused to occur by providing free agitator rotation between defined limits but such that continued rotation of the agitator in one direction or the other will cause rotation of the bowl in the same direction by engagement of buffer 21 with the arm 22.

To give these actions a preferred electrical supply and motor control circuit will be described which will give the preferred functions that must be performed which are firstly control of motor speed at one of several selected levels which are substantially independent of motor load within a defined range of loads, secondly control of orderly acceleration deceleration and reversing of the motor, thirdly control of braking from a spin or other speed with or without the presence of main supply voltage and initiated either by external means such as opening of the spin drum lid or internally such as by loss of mains power, and fourthly control of orderly transfer from one demanded mode of operation, for example agitation, to another for example spin, as requested either by for example a mechanical appliance timer circuit or control microprocessor, and as required for correct functioning of the overall electro-mechanical drive package.

A circuit to perform these functions will now be described.

With reference to figure 3 the motor 15, which is to be controlled, is as stated, a direct current reversible motor of a type which can have its speed controlled by controlling the average DC voltage applied across the motor and which can be reversed by reversing the polarity of the voltage across the motor, for example a permanent magnet commutator DC motor. The circuit is supplied from e.g. 240v 50 cycle AC supply at P+ N and through a full wave rectifier circuit 26 and a reservoir capacitor 25 is connected across the DC leads rails A and OV from this rectifier DC voltage supplied to rails A and D the latter being the OV supply common rail. A low voltage power supply 26 is provided and is in part an AC to DC converter and in part a DC to DC converter.The motor 15 is arranged in the centre of a reversing bridge and current path selection circuit comprising for example a network of switching devices for example changeover relays having magnetically actuated movable contacts and fixed contacts 30, 31, 32 and 33 and diodes 34, 35,36 and 37.

Thus the motor can be driven in one direction by current flowing along the pathway from rail A, diode 34, contact 30 motor 15, contact 33, diode 37, power modulating switch 38 and a current sense resistor 39 to common supply OV. The motor can be driven in the opposite direction by currentflowthrough diode 35, contact 32, motor 15, contact 31, diode 36, switch 38 and resistor 39, Switch 38 is a power modulating switch which may, for example, be a power bi-polar or power field effect transistor, a gate turn off thyristor or other similar device. The switch 38 is used to modulate the application of supply voltage to the motor 1 5 thus for example if switch 38 is on for 50% of the time the motor 1 5 experiences a drive voltage equivalent to approximately 50% of the supply voltage.If the switch 38 is on for say 5% of the time then the motor 15 experiences a drive voltage equivalent to approximately 5% of the drive voltage. The total switching period may be of the order for example about 100 microseconds.

Other devices used in the circuit are introduced into the following description of the operation of the circuit and a typical switching cycle in simplified form is as follows: For example contacts 30 and 33 are made if not already in that configuration, a short period prior to switch 38 being turned on. When switch 38 has been turned on, current builds up in the motor circuit loop through diode 34, contact 30, motor 15, contact 33, diode 37, switch 38 and resistor 39. The drive current is principally determined by firstly the current flowing in the circuit loop of diode 34, contact 30, motor 1 5, contact 32, diodes 37 and 44 at the moment of turn on, secondly the values of inductance and resistance associated with motor 15, and thirdly the motor back EMF and finally the supply voltage of circuit rail A relative to OV rail D.

A controller circuit 40 is provided connected to relay coils and drive circuit 29 to control operation of the contacts 30 to 33 and also via a demanded speed selection circuit 41 and a switching regulator 42 to control switch 38.

Motor current is sampled by the motor current limit circuit 43 across a current sensing component, preferably current resistor 39. Motor current information is fed to switching regulator 42, e.g. an (SR) IC, and this may be used to terminate the on-time of switch 38 should excessive current flow be sensed in the resistor 39. This may be achieved in the manner common to switching motor speed or voltage regulator circuits. Thus the maximum current that can flow through resistor 39 is limited. If the current is not excessive termination of the "on' period is controlled by the switching regulator 42 in conjunction with controller 40 at a percentage cycle on time appropriate to achieve the desired rotational speed of the motor 1 5.At turn off, the inductance associated with the motor 15 attempts to keep current flowing and would cause the voltages at the circuit rail B to rise to potentially damaging levels if preventive measures were not taken. Accordingly, diode 44 is provided to allow motor current to continue to flow in the loop comprising diode 34, contacts 30, motor 15, contact 33 and diodes 37 and 44. The principal purpose of capacitor 34 and resistor 46 is to control the safe operating area loci for example as is normal in the switching of inductive loads with bi-polar transistors.

Thus the effective motor drive voltage is controlled through the percentage on to off times of switch 38 as switched by switching regulator 42 which is in part a feed-back control circuit, error amplifier and modulator, for example as used in the switch control of motor speed. Such a circuit requires input information in the form of demand and actual speed and this is delivered in current analogue form to the error amplifier summing point C.

The information on motor speed is derived indirectly in order to minimise the costs of components and by means which require no tachometers or velocity pulse generators. By approximating the motor as an equivalent circuit having series resistance R and back EMF E, the speed can be approximated as being proportional to E which is the effective motor terminal voltage V less the I x R drop where I is motor current.

Thus the speed is proportional to V - IR.

The term for I is obtained by using a circuit 47 which is essentially a peak-hold circuit which looks at the pulse that appears across resistor 39 during the "on" time of switch 38 and is arranged to transform this to a continuous scale current representative of IR which is delivered to the summing point C.

The term for V is derived by measuring the voltage across the motor, which is, to sufficient accuracy, the voltage at circuit rail B with respect to the supply voltage at rail A. Use is made of the fact that the voltage at rail B is a switched waveform rather than a steady DC voltage, in order to translate this waveform to a stream of current pulses. The length of these pulses is dependent upon the on-time of switch 38 and the magnitude of these pulses is dependent upon the instantaneous value of the supply voltage at rail A. This pulse train is fed to summation point C and integrated to give an analogue of motor voltage.

The circuit can be built for either polarity of supply with appropriate changes to the polarized components for example the diodes transistors and the like but for the purpose of this description the supply will be considered as positive to OV supply common rail D. The description of circuit operation will also assume a zero voltage drop across diodes in the forward direction.

The demanded speed selection circuit 41 is provided from known art for selecting desired motor speed which is transformed and delivered to the summing point C from circuit 41 as the current analogue of desired speed. It will be apparent how the current analogues of desired speed, motor terminal voltage, and motor current, when delivered to the summing point C are used to derive drive pulses on lines E and F and associated drive circuit to control switch 38 and thus provide closed loop feed-back control of motor speed.

Controller 40 and switching regulator 42 provide other functions as follows: (a) Termination or suppression of drive pulses in over current conditions.

(b) Control and sequencing of relay switching contacts 30 to 33 and switch 38 as required for agitation, spin and braking operations.

(c) Control sequencing of relays switching contacts 30, 33 and 38 as required for braking operations.

Describing these functions and for the transitions between these operations in turn: (a) Motor current limit circuit 43, which can be based on known circuits, derives motor current information from the voltage pulses across resistor 39, provides selectable scaling and optionally low pass filtering and passes this information to switching regulator 42 at the correct time for it to terminate or suppress drive pulses as is common with switching regulator circuits. Selection of scaling may be by any means suitable to the application.

(b) Diodes 34 to 37 and the control and sequencing of relay contacts 30 to 33 and switch 38 select motor direction or braking modes of operation and have due regard for need for proper switching of inductive currents and avoidance of short circuits.

(c) The next section describes the braking function.

The braking means consists of parts of the circuit described so far with the addition of a relatively low resistance current pathway including diode 50 and a relatively high resistance current pathway including resistor 51. Braking from a speed controlled mode operates as follows: Motor stopped detection circuit 52 is in the current path which is common to the relatively low resistance braking path including diode 50 and the relatively high resistance braking path including resistor 51 and detector circuit 52 therefore conducts braking current at all times during the braking mode of operation. A signal is fed from circuit 52 to controller 40 upon completion of braking and controller 40 is then allowed to set up the reversing bridge and current path selection circuit for any other mode of operation e.g. agitate.

In braking mode contacts 31 and 33 are closed.

Switch 38 is turned on and current builds up at a rate determined by the back EMF of motor 1 5 and the circuit inductances and resistances around the loop consisting of contact 31, diode 36, switch 38, resistor 39, diode 50, circuits 52, contact 33 and motor 15. In the braking mode the switch 38 is switched at frequencies similar to those used in the speed control mode. The pulses are derived from the switching regulator circuit 42 which controls speed but the modulator is set for maximum on time by controller 40 in conjunction with demanded speed selection circuit 41. As soon as sufficient braking current is flowing pulse termination or suppression using the same circuits as in the speed controlled mode is used to control steady flow of braking current at a level selected through motor current limit circuit 43 as controlled by controller 40.

When turn off of switch 38 occurs the current flowing changes its path. Snubber/filter components 45 and 46 modify the waveforms if necessary to ensure safe and satisfactory operation of the circuit. After turn-off, current flows in a loop comprising motor 15, contact 31, diode 36, resistor 51, circuit 52 and contact 33.

During turn on, the back EMF of the motor 15 is used to store energy in the inductance in motor 1 5. At turn off, the rate of change of current in the inductance generates voltage to force the current around the new path and so dissipates energy principally in resistor 51. Resistor 51 may be sized so that the voltage developed across resistor 51 by current flow therein is a convenient level, perhaps a little below normal supply voltage.As switch 38 is controlled to turn off at a defined current level and this current is divertable through resistor 51 which is of a defined value, then it is possible during the turn off period to develop a constant voltage across a single fixed energy dissipating resistor independent of the back EMF of the motor providing only that the back EMF is sufficient to develop the necessary limiting level of current in the relatively low braking current path including diode 50 during turn on.

It is thus possible to achieve controlled current braking of the motor independently of motor speed if desired typically down to 5% or 10% of full speed, and with the use of a single fixed value braking resistor. The controlled current may be controlled as a function of speed or time by circuit 43 and upon command from controller 40 using known means or simply held at a constant value.

It is desirable that a safety braking function operates whether mains supply voltage is present or not and braking performance can be achieved with no mains supply until the motor ceases to rotate or at least rotates only slowly, perhaps 10% of full speed.

This is achieved by feeding current from the high voltage source developed at point B during braking through diode 44 to reservoir capacitor 25 and so to power supply 26 which is in part a DC to DC converter and provides low voltage power to the control circuits and because the back EMF is used to generate the aforementioned high voltage during braking, the power supply 26 does not experience any significant drop in input voltage until the motor is almost stationary, even in the absence of mains supply.

By maintaining the low voltage for the control circuits and because braking current relies on the presence of the back EMF only and not the supply voltage, braking is controlled down to low speed even in the absence of mains supply.

Normal drive power for the motor is provided by direct rectification of the AC mains supply by diode bridge 26. Capacitor 25 provides smoothing and resistor 27 control inrush currents. Capacitor 25 and resistor 27 may be sized to control the harmonic current flowing in the mains supply lines. For more general use other supply means such as batteries may be used.

With a battery supply or other supply capable of storing full braking energy, resistor 51 may be omitted and regenerative braking achieved, because braking energy is returned to the battery via diode 44 in the supply. By the addition of extra components to mirror the existing relatively high resistance braking circuit including resistor 51 and connected symmetrically on the other side of the motor, braking may be performed from either direction of rotation. Regenerative and bidirectional braking are features that make the circuit suitable for vehicle use or as a general purpose drive controller.

The equipment will run the motor at reversal rates down to any required lower limit and the spinning speeds are limited only by mechanical requirements and motor characteristics. However in practical parameters for example with an agitator and spin bowl of a washing machine, cyclic reversal of the relays 29 allows reversal of direction of the motor at for example a relatively low speed e.g. 14 RPM maximum of the motor to obtain an agitator action within the bowl and also high speed rotation e.g. 17000 RPM of the motor being at 14:1 speed reduction between motor pulley and pulley 12, a spin bowl speed of about 1200 RPM in one direction of the agitator and bowl can be achieved for a spinning operation to remove substantial water or moisture from, for example, clothing within the bowl. Thus the ratio of motor speeds between spin and agitate can be greater than 10:1 and are preferably less than 15:1 in practical applications also.

Furthermore during, for example, supply voltage failure or when the mains supply is switched off the back EMF of the motor can be used to keep the control circuits powered up until a relatively low level of bowl rotation has been reached.

Thus it is an advantage of at least a preferred form of the invention that a vertical axis washing machine can be designed and constructed with less moving parts and for a potentially lower cost than has been possible up to this point in time.

Furthermore other advantages, features and operational characteristics of the preferred form of the invention are as follows: 1. The relay contact circuit used is a low cost means of reversing a DC motor when combined with a semi-conductor device as a power switch.

2. A standard switching regulator (SR) IC is used as a control element.

3. Current limit is achieved by the use of the SR IC during the speed control phase.

4. Speed control is achieved by generating the necessary MSR (mark space ratio) based on average motor current, motor resistance, average motor drive voltage, and known voltage constant.

5. Low voltage semi-conductors are used as voltage feed-back.

6. If desired a soft feature is optionally provided for the control of mechanical shock using standard features of the SR IC.

7. The use of motor back EMF and inductance is used to generate a constant voltage for application across a braking resistor instead of only speed proportional back EMF. Use of only one braking resistor is an advantage.

8. The circuit uses back EMF and inductive kick to keep the low voltage power supply alive through a switching regulator so as to enable braking to be completed even after the loss of mains power.

9. Use of the same SR IC and the same switching transistor is used for speed control to sample braking current through the current measurement resistor and to regulate braking current as required.

10. Zero speed demand is used to allow relay contact current to decay during direction or mode changing to prevent contact arcing.

11. Control circuit referenced to negative output of the bridge rectifier is used thus simplifying the drive circuits for the switching transistor and current sensing.

12. The circuit has the ability to use a fixed period between agitate motions to allow the agitator to come to rest so that the electrical energy is not wasted in plugging the motor, and to make full use of the initially stored energy, if desirable and dependent upon the load.

13. Only one free wheel diode is used across the complete H network. 14. The current limit may be different for agitate and braking spin modes and accelerate to spin speed on spin current limit.

15. Profiling of the braking current to the maximum within the current vs speed profile is used.

16. The mains voltage switching enables the use of standard timers, switches and contacts.

17. Controller 24 may be used to vary the speed of the motor within the period of an agitator stroke and so the agitator speed-time profile can be tuned to a desired shape in order to optimise washing efficiency.

18. Controller 24 may be used to provide the user with several selectable combinations of agitator speed profiles and agitator reversing rates to provide a useful range of washing actions to cope with various conditions.

19. Controller 24 may be used to provide the user with several selectable spin speeds and the value of these speeds and the rates of acceleration up to these speeds can be set during production to suit differing washing machines and/or performance requirements.

Claims (1)

1. A method of actuating a clothes washing machine of the type described, said method including the steps of, in the agitating phase using an electric motor connected to said agitator through a speed reducing transmission to rotate first in one direction and then in the other so that said agitator in turn is rotated over angular rotations in each direction in less than 27r radians and in said spin phase causing said motor to be connected to said bowl and to rotate the latter continuously in one direction at a higher speed.

2. A method as claimed in claim 1 which includes the step of limiting the angular rotation of said agitator to less than 27r radians.

3. A method the step of arranging the ratio of motor speeds to be greater than 10:1 as between spin speed and maximum agitating speed.

4. A method as claimed in any one of the preceding claims in which the motor speed ratio is less than 15:1.

5. A method as claimed in any one of the preceding claims which includes the steps of cyclically actuating relays to change over contacts through which power is suppled to said motor to cause reversal of said motor during the agitate phase of operation.

6. A method as claimed in claim 5 which includes the steps of stopping current flow through said changeover contacts before changeover is effected and restraining current flow after changeover is effected.

7. A method as claimed in any one of the preceding claims which includes the steps of braking said motor by converting the kinetic energy of moving parts into electrical energy and absorbing that energy.

8. A method as claimed in claim 7 which includes the steps of absorbing said energy by connecting the motor terminals to a resistor.

9. A method as claimed in claim 8 which includes the steps of controlling the supply of back EMF from the motor to said resistor so that a constant voltage is applied to said resistor down to low speeds of the motor.

10. A method as claimed in any one of claims 7 to 9 which include the steps of limiting the rate of generating electrical energy during braking.

11. A method as claimed in any one of claims 7 to 10 which includes the steps of using the back EMF from said motor to supply a required portion of the controlling circuit with electrical energy during braking.

12. A method as claimed in any one of claims 7 to 11 which includes the steps of passing braking current through either a first relatively low resistance current path from a terminal of said motor, said low resistance current path including said power regulating switch or a second relatively high resistance current path from said terminal and a common current between the other terminal of said motor and said high and low resistance current paths, said common current path including one said fridge switch, said current being generator in use by the back EMF of said motor, said back EMF generated current representing the storage of energy in the inductances of the circuit, principally in the motor, applying to a storage capacitor a voltage generated across said high resistance current pathway and using the power supply associated with said storage capacitor to supply power to circuit componentry substantially independent of any supply voltage and substantially independent of the back EMF generated until said back EMF has dropped to a substantially low voltage.

13. A method as claimed in any one of the preceding claims which includes the steps of monitoring motor current and actuating switching means to limit that current to less than a predetermined value.

14. A method as claimed in any one of the preceding claims which includes the steps of controlling motor drive voltage by controlling the on off times of a power modulating switch in respect to input information relating to demanded speed and actual speed of the motor.

15. A method as claimed in claim 14 includes the steps of providing information on motor speed by measuring the effective motor terminal voltage V measuring the current I by resistor R voltage drop in the motor and less the voltage V - IR as being indicative of motor speed.

16. A method as claimed in claim 15 which includes the step of measuring the current I by obtaining a voltage across a resistor through which current I is passed.

17. A method of actuating a clothes washing machine when effected substantially as herein described with reference to and as illustrated by the accompanying drawings.

18. Apparatus for actuating a clothes washing machine, said means comprising an agitator shaft, an agitator mounted on said shaft, a hollow spin shaft coaxial with said agitator shaft, a spinning bowl mounted on said spin shaft and in which said agitator is mounted, an electric motor having a drive shaft, a speed reducing transmission means connecting said driving shaft to said agitator shaft so that rotation of said driving shaft in one direction or the other causes rotation of said agitator shaft in the same sense as the driving shaft, a lost motion device between said agitator shaft and said spin shaft permitting said agitator shaft to rotate in either direction without causing material rotation of said spin shaft and electric supply and control means supplying said motor with current so that in an agitating phase, said motor is rotated cyclically first in one direction then in the other to cause said agitator to oscillate without causing said bowl to be moved materially from a stationary position, and in a spin phase causing said motor to rotate continuously so that free play in said last rotation device is taken up and said bowl caused to spin at spinning speed, said electric supply and control means controlling the energy suppled to said motor so that the spinning speed is at least ten times the maximum agitating speed of said motor.

19. Apparatus as claimed in claim 18 wherein said lost motion device comprises a pin at a radius from the longitudinal centre of said agitator shaft, said pin being arranged to be driven by said motor and an arm being a radius greater than said radius of said pin, said arm being fixed to said spin shaft and arranged to be driven by said pin when said means are in the spin mode.

20. Apparatus as claimed in claim 18 or claim 19 wherein at least two balance weights are pivotally mounted on said spin shaft.

21. Apparatus as claimed in any one of claims 18 to 20 wherein said speed reducing transmission comprises a belt and pulley arrangement having a speed change ratio of between 8:1 and 20:1.

23. Apparatus as claimed in any one of the preceding claims wherein said supply and control means include relay operated changeover switches and diodes to control reversal of said motor during the agitation phase of operation.

24. Apparatus as claimed in claim 23 wherein said relays are cyclically actuated by a controller.

25. Apparatus as claimed in claim 23 or claim 24 wherein switching means are provided which stop current flow through changeover contacts of said relay before changeover commences and start current flow therethrough after changeover has been effected.

26. Apparatus as claimed in claim 25 wherein said switching means comprise a power modulating switch.

27. Apparatus as claimed in any one of claims 18 to 26 wherein braking means are provided comprising energy absorbing means and means to connect the same to terminals of the motor to absorb electrical energy therefrom.

28. Apparatus as claimed in claim 27 wherein said braking means include a first relatively low resistance current path from one of said terminals of said motor, said low resistance current path including said power regulator switch, and a second relatively high resistance current path from said terminal, a common current path being provided between the other terminal of said motor and said high and low resistance current paths, said common current path including one said bridge switch, said current paths passing current generated in use by the back EMF of said motor, said back EMF generated current representing the storage of energy in the inductances of the circuit, principally in the motor, said control circuit further including a storage capacitor receiving current generated by means of the voltage drop across said high resistance current pathway and a power supply associated with said storage capacitor to supply power to circuit componentry substantially independent of any supply voltage and substantially independent of the back EMF generated until said back EMF has dropped to a substantially low voltage.

29. Apparatus as claimed in claim 28 wherein a resistor is provided connected during braking to said motor and into which braking energy is discharged.

30. Apparatus as claimed in claim 29 wherein voltage control means are provided to control the voltage applied to said resistor to a substantially predetermined figure until braking has been almost completed.

31. Apparatus as claimed in any one of claims 28 to 30 wherein the same SR IC and the same switching transistor are used for speed control to sample braking current through the current measurement resistor and to regulate braking current as required.

32. Apparatus as claimed in any one of claims 28 to 31 wherein means are provided to limit the rate of generator electrical energy during braking.

33. Apparatus as claimed in any one of claims 18 to 32 wherein current limiting means are provided to limit current drain by said motor to within predetermined limits.

34. Apparatus as claimed in any one of claims 18 to 33 wherein motor drive control means are provided controlling a power modulating switch to control motor speed.

35. Apparatus as claimed in claim 34 wherein speed control means comprise means to generate a mark space ratio voltage based on average motor current, motor resistance, average motor drive potential and a known voltage constant.

36. Apparatus as claimed in any one of claims 18 to 35 which includes circuitry whereby motor back EMF and inductance are used to generate a constant voltage for application across a braking resistor instead of only speed proportional back EMF.

37. Apparatus as claimed in any one of claims 18 to 36 which includes circuitry whereby back EMF and inductive kick to keep the low voltage power supply alive through a switching regulator so as to enable braking to be completed even after the loss of mains power.

38. Apparatus as claimed in claim 37 wherein a diode controls the voltage generated by said inductive kick.

39. Apparatus as claimed in any one of claims 18 to 38 wherein circuitry is provided to permit zero speed demand to be used to allow relay contact current to decay during direction or mode changing to prevent contact arcing.

39. Apparatus as claimed in any one of claims 18 to 38 wherein circuitry is provided to permit zero speed demand to be used to allow relay contact current to decay during direction or mode changing to prevent contact arcing.

40. Apparatus as claimed in any one of claims 18 to 39 wherein circuitry is provided so that control circuit referenced to negative output of the bridge rectifier is used to simply the drive circuits for the switching transistor and current sensing.

41. Apparatus as claimed in any one of claims 18 to 40 wherein circuitry is provided to use a fixed period between agitate motions to allow the agitator to come to rest so that the electrical energy is not wasted in plugging the motor, and to make full use of the initially stored energy, if desirable and dependent upon the load.

42. Apparatus as claimed in any one of claims 18 to 42 wherein low voltage semi-conductors are used as a drive voltage feedback.

43. Apparatus as claimed in any one of claims 18 to 42 wherein circuitry is provided to control current in said motor to give desired positive or negative acceleration of said motor.

44. Apparatus as claimed in claim 43 wherein said circuitry to control current in said motor provides different current limits for agitate and braking from spin modes and accelerate to spin speed on spin current limit.

45. Apparatus as claimed in claim 43 or claim 44 wherein said circuitry to control current in said motor provides the braking current to control current in said motor provides the braking current to the maximum within the current vs speed profile used.

46. Apparatus as claimed in any one of claims 18 to 45 wherein said control means include a controller to vary the speed of the motor within the period of an agitator stroke and so the agitator speed time profile can be tuned to a desired shape in order to optimise washing efficiency.

47. Apparatus as claimed in claim 46 wherein said controller is programmed to provide the user with several selectable combinations of agitator speed profiles and agitator reversing rates to provide a useful range of washing actions to cope with various conditions.

48. Apparatus as claimed in claim 46 or claim 47 wherein said controller is programmed to provide the user with several selectable spin speeds and the value of these speeds and the rates of acceleration up to these speeds can be set during production to suit differing washing machines and/or performance requirements.

49. Apparatus as claimed in any one of claims 18 to 48 wherein mains voltage switching is provided controllable manually or by time switches to give desired sequences of operation.

50. Apparatus for actuating a clothes washing machine when constructed arranged and operable substantially as herein described with reference to and as illustrated by the accompanying drawings.

51. A clothes washing machine incorporating apparatus according to any one of claims 18 to 50.

52. Any novel feature or combination of features described herein.