Patent GB-477254-A (GB)
Title: Improvements in or relating to the control of washing or dyeing machines
IPC: D06B23/00
Filed: 1937-05-21
Abstract: <PICT:0477254/IV/1> <PICT:0477254/IV/2> The apparatus described in the parent Specification is modified in two respects, namely in that liquid-level and thermally-operated devices are substituted for the time-controlled devices for closing the valves which have been opened by the time control, and secondly in that a variable-speed drive is provided for the controller whereby, whatever the duration of any formula, one complete rotation of the controller is always required for the operation of that formula thereby eliminating the wait during the power-rotation of the controller through a blank portion due to a short cycle or the necessity for rotating the controller manually through such blank portion.  A float working in a chamber which is in fluid communication with the washing-machine is connected to a slidably-mounted block 16 on which a trip lever 15 is pivoted, the block rising with the float. A number of mercury switches corresponding to the number of levels which the washing or other liquids may be required to assume during the various stages in the washing cycle, are arranged in the path of the lever and are closed successively as the float rises.  Each switch is connected to studs arranged concentrically on a stationary disc and swept by contacts carried by a rotating arm driven by the timing drum of the parent Specification.  Only one of the contacts on the rotating arm is energized at any time, the particular one being determined by the particular formula being operated, and the selection of this one being effected by a mechanical coupling to the manually operated knob provided for selecting the formula.  The circuit to any valve closing mechanism is thus completed only when the particular stud corresponding to a predetermined depth is energized by the closing of the appropriate mercury switch and is contacted by the preselected contact on the rotating arm, the closing of the other mercury switches being without effect as the studs corresponding thereto are not, for the time being, in the path of the preselected contact on the rotating arm.  The timing drum is stopped during the time that the supply valves are open and is restarted by relay devices operated by the depth switches and controller.  The temperature control for controlling the supply of heating steam comprises a bar 71 on which a number of mercury switches 72 are set at different inclinations corresponding in number to the different temperatures at which the control is to function.  The bar is rotated by a pinion and quadrant mechanism rocked by a Bourdon tube connected to a bulb of fluid anchored in the washing-machine.  Each switch is in circuit with the rotary selector operated by the timing drum so that, although the switches close successively, only that particular one corresponding to the required working temperature becomes operative to close the circuit to the steam-supply valve-closing means through the particular preselected contact on the rotary selector.  The second modification of the invention of the parent Specification is effected by coupling a rotary selector switch to the formula-selecting handle whereby more or less resistance is put into the circuit of the motor driving the control drum so that the shorter the duration of any particular formula selected the faster the motor and control drum rotate.