GB1258839A - - Google Patents

Abstract

1,258,839. Washing machines. MATSUSHITA ELECTRIC INDUSTRIAL CO. Ltd. 12 Nov., 1969 [15 Nov., 1968], No. 55483/69. Heading D1A. In a washing machine with a pulsator mounted within a washing drum and a time switch providing a series of cycles from washing through rinsing to drainage, rinsing detection means are provided which stop the drive of the time switch during the rinsing cycle until its completion and comprise a luminous element 8 and a photosensitive element 9 for detecting the transparency of the washing water and control means for controlling the drive of the time switch. As shown, liquid overflow from the drum during rinsing enters a sampling box at 10 and leaves at 11, detergent in the liquid causing bubbles to form in the box, which bubbles in rising to an air outlet 12 prevent actuation of the Cd S cell 9 until the rinse water is free of detergent. In a modified arrangement (Fig. 10) part of the overflow passes through a by-pass tube C and thereby draws air through holes E to maintain the flow through the sampling box 7 sensibly independant of the total overflow. In a further alternative the sampling box is disposed in the drum. In operation the drum is first filled through a water valve 30 by closing a switch 21 until a water level switch 24 is changed from contact 'a' to 'b' thereby starting a timer motor 28 and the reversing pulsator drive motor 29 to start the washing cycle. At the end of the wash cycle time the contact 'a' of the switch 24 is closed to again introduce water for rinsing until the contact 'b' is closed again to actuate the pulsator motor 29 while a switch 23 is closed to maintain the water flow and cause overflowing. After a set time to permit stirring up of the detergent in the wash, switches 38 and 39 are closed to energise the lamp 8 and to discharge a capacitor 40. This switches on the transistor 47 and operates an electromagnet 45 to raise a gear (50) (Fig. 7 not shown) in the timer drive, the gear closing a switch 46 when raised which is connected to the photocell element 42. In addition a switch 43 is closed when the rinse water is well mixed, such as during clockwise rotation of the agitator, at intervals until the water becomes clear, when the photocell resistance is reduced and the transistor switch 47 operates to release the gear (50) and thus continue the wash programme. The operating point of the photocell is adjustable by a potentiometer 44.