The present invention relates to a washing machine comprising detergent dispensing means provided with a plurality of separate compartments for containing wash and/or rinse products to be added into the tub of the machine. Such known detergent dispensing means comprise usually a rotating selector capable of being displaced into various operational positions by appropriate driving means so as to enable the inflowing water to selectively flow through each one of said compartment.

Detergent dispensers for washing machines such as clothes washing machines and/or combined clothes washing and drying machines are known in the art, which are divided into a number of separate compartments intended for holding the various pre-wash and main wash detergents, as well as the various rinsing aids such as the bleaching agent and/or the fabric conditioner, wherein each such compartment is capable of being selectively flushed by the water flowing in from the supply mains and directed into said compartment by means of a suitable rotating compartment selector, which is capable of being displaced into its various operational positions by means of suitable linkage means operable by one or several profiled cams of the programme-sequence/timer control of the washing machine so as to thereby cause the water to flow into the wash tub of the machine together with the detergent or rinse aid contained in the compartment being from time to time flushed.

DE 4335600 A and GB-A-2062015 disclose different mechanisms from the detergent dispenser according to the present invention. EP-A-0504545 discloses a control arrangement for washing machines.

The known detergent dispensers use the existing motor on the electromechanical or hybrid timers by means of a wire, springs, cams and other components. For washing machines provided with electromechanical timers, the motor is already included in the timer. For modern washers equipped with a full electronic control, a step motor for controlling the compartment selector is added, and a feedback of the selected dispensing system is required.

The movable element of the selector can be a simple lever carrying a water nozzle which directs the water toward one of the compartments, or it can be a rotating distributor having channels for conveying water to different detergent dispensers according to the angular position of the selector. The cost of known detergent dispensers is presently high due to the number of mechanical components linked to it. Moreover the mechanical system for moving the selector is quite complicated and therefore its reliability is not very high.

It is a purpose of the present invention to provide a detergent dispenser associated with a washing machine having a low cost and a high reliability due to an inherent simplicity of the system linking the electric motor and the selector.

A further advantage of the technical solution according to the present invention, beside the reduction of the overall cost of the machine, is that the detergent dispenser can use the full torque in forward and backward movement of the selector that is available at the actuator in order to overcome any blockage problems.

The detergent dispenser according to the invention is implemented with the construction characteristics as essentially set forth and described in the appended claims. The invention will anyway be hereinafter further described by way of non-limiting example for better understanding, with reference to the accompanying drawings in which:

• Figure 1 is a perspective view of a section of a detergent dispenser for washing machines according to the present invention;
• Figure 2 is a partially sectioned and enlarged view of a detail of figure 1, and
• Figures 3-6 are top view of a portion of the detergent dispenser of figures 1-2 which show different configurations thereof.

Figure 1 shows a detergent dispenser 10 which is installed in the usual way in the upper portion of a washing machine (not shown), particularly of a drum-type clothes washing machine or combined clothes washing and drying machine, and is constituted by a drawer-like reservoir 12 provided with a plurality of separate compartments (not shown) intended to contain the various washing detergents and/or rinsing aids to be added in a selective manner into the wash tub of the washing machine where they will be used for carrying out the various steps and phases of each selected clothes washing process. The drawer-like reservoir 12 is slindingly insertable in a box shaped recess 12a installed in the front portion of the washing machine, just below the top surface of the machine. As it can further be seen, a hose 14 is in communication, downstream electrical on-off valve 16, with a nozzle 18 inside the recess 12a which directs the water flow towards a rotating selector 20 placed inside the recess 12a, at one end thereof, far from the front face of the washing machine. The box shaped recess 12a further comprises flexible hoses 15a and 15b for its hydraulic connection to the tub of the washing machine. The compartments of the drawer-like reservoir 12 are supplied in a selective manner with the cold and/or hot water flowing in from the pipe 14, by means of the rotation of the selector 20 up to certain predetermined positions.

The selector 20 is driven by means of a lever system L which comprises a first crank 22 keyed on an axle 24a of an electric motor 24 connected to the recess 12a, a connecting rod 26 and a second crank 28 keyed to the vertical axle 20a of the selector 20, placed outside the upper wall of the recess 12a.

The electric motor 24 is a synchronous (?) motor and it has only one sense of rotation, it is connected to the control unit of the machine and its axle, and therefore the crank 22 keyed thereto, is able to assume certain predetermined position, for instance in the shown example four different positions. The length of the cranks 22 and 28 and of the connecting rod 26 is selected in order to have an oscillating back and forth movement of the selector 20 (between two predetermined end positions I and IV) when the axle 24a of the electric motor makes a complete turn.

In figure 3 it is shown a first position of the crank 28, corresponding to the feeding of water towards a first compartment I, for instance corresponding to the main wash. In figure 4 the selector 20 feeds water towards a second compartment II, corresponding for instance to bleach. The third configuration, in which water is fed to a third compartment III, corresponds to the use of softener in the washing cycle, while the fourth compartment IV is used for auxiliary purposes.

It is clear how the construction of the detergent dispenser, and particularly of its drive system, is very simple and with a reduced number of components if compared to the known detergent dispensers. Moreover, it does not use any spring or
profiled cams of the programme sequence/timer control device of the washing machine.

For sake of simplicity, some components have not been described, for instance micro-switches or similar electrical switching means included in the electrical circuitry of the washing machine in order to give a position feedback concerning the actual configuration of the selector 20. Anyway, such components and use thereof are well known in the art of washing machines.

In order to displace the compartment selector 20 into each one of its various control positions, the control unit energises the motor 24 so that the selector 20 is rotatably driven to advance to its immediately next control position under resulting closure of the corresponding micro-switch and activation of the operational component part of the machine which is associated with that micro-switch. The control unit subsequently acts so as to recognise and identify the control position reached in the above described way by the rotating compartment selector 20, as well as all the subsequent control positions which will in that way be reached by the selector, by detecting the closed state of the corresponding micro-switch and identifying it. Of course it is possible to replace microswitches for instance with a step motor.

Owing to the fact that said rotating selector 20 is rotatably driven into its various control positions at a predetermined speed rate by the corresponding synchronous motor 24, this means that it is not necessary any mechanical link with the programme sequence/timer control device of the known machines, therefore allowing the designer to install the same detergent dispenser according to the present invention either on a machine provided with a traditional timer or on an electronic-controlled washing machine