Liquid detergent dispensing apparatus for washing machines

Claim 1

A liquid detergent dispensing apparatus for use in a washing machine, the washing machine including a wash tank, a liquid detergent reservoir, and a multicompartment detergent container in fluid communication with the wash tank and in fluid communication with the detergent reservoir via a metering pump, the multicompartment detergent container having an actuator associated therewith which is responsive to a control device to place at least one compartment of the multicompartment detergent container in fluid communication with the wash tank, the washing machine further including a heating element which is responsive to the control device to heat a solution of the wash tank, the washing detergent dispensing apparatus comprising: setting means for setting a quantity of liquid detergent to be added to the wash tank, wherein said setting means includes an oscillator for generating a first pulse signal having a frequency which is variable, the frequency of the first pulse signal corresponding to the quantity of liquid detergent to be added to the wash tank; and, drive means, operatively coupled to the heating element and the metering pump and the actuator and said setting means, for selectively driving the metering pump for a period of time corresponding to the quantity of liquid detergent set by said setting means in response to an operating state of the actuator and the heating element; wherein said drive means comprises (a) a frequency multiplier means, operatively coupled to said oscillator, for operating in an enabled state to generate a second pulse signal having a frequency which is a multiple of the frequency of the first pulse signal generated by said oscillator, (b) logic circuit means, operatively coupled to said frequency multiplier means and the actuator, for enabling said frequency multiplier means in response to the operating state of the actuator, (c) electronic counter means, operatively coupled to said frequency multiplier means, for operating in an enabled state to count the pulses of the second pulse signal generated by said frequency multiplier means, (d) sensor means, operatively coupled to said electronic counter means and the heating element, for enabling said electronic counter means in response to an operating state of the heating element, and (e) metering pump drive means, operatively coupled to said electronic counter means and the metering pump, for operating in an enabled state to cause the metering pump to dispense liquid detergent from the reservoir in response to an output from said electronic counter means, wherein the electronic counter means enables said metering pump drive means while counting a number of pulses generated by said frequency multiplier means while being enabled by said sensor means.