Patent GB-730374-A (GB)
Title: Work treating machines
IPC: D06F34/08
Filed: 1951-05-23
Abstract: <PICT:0730374/III/1> A washing or dry-cleaning machine comprises a container 170 for work provided with a drain valve 155, valve controlled means for supplying treating liquid thereto, means for releasably maintaining the valve controlled means open, level control means adapted to be preset by the operator for releasing the maintaining means when the liquid reaches a predetermined level, and means for rendering the maintaining means ineffective unless the level control means has been preset.  The invention is described as applied to a washing machine.  Liquid level control.-The liquid level is determined by pressing one of three buttons 118a, 118b and 118c, controlling switches 125a, 125b and 125c respectively.  Three air-operated bellows 148a, 148b and 148c operate switches 150a, 150b and 150c respectively through spring-pressed studs 149, the springs on these studs being adjusted to different tensions.  When liquid is flowing into the container 170 air is bubbling into the liquid through a tube 171 and encounters increasing resistance.  The tube 171 is in communication with the three bellows so that as the level rises in the machine the pressure increases until bellows 148a operates switch 150a.  If button 118a has been depressed the liquid supply stops.  If not, the supply continues until the level corresponding to button 118b or 118c is reached.  Liquid temperature control.-In the example, hot and cold liquids are supplied by pipes controlled by valves 169, 169a.  Air pressure applied through pipes (as 168) opens the valves either the whole or half way, so that by appropriate selection the washing liquid may have any one of five temperatures.  The selection is made by means of four push-buttons 117 controlling valves 123a, 123b, 123c and 123d.  Operation.-To start the machine, a lever 112a is operated to open an air valve 112c and close a switch 112b.  The effect is to light a red lamp 115 and energize a solenoid 181 operating a valve 183 controlling an air-operated whistle 151.  The operator then sets the knob 107a of a timer motor 107 to the desired time interval of treatment thereby opening switches 108, 109, shutting off the whistle 151, starting the timer motor and turning on a green light 114.  The liquid level is then determined by pressing one of the buttons 118a, 118b or 118c, thereby moving one of the switches 125a, 125b or 125c to a second position, and stopping the timer motor.  A button 116 is now depressed, closing a switch 143 and allowing air to flow through a valve 137 to a motor 152 to close the drain valve 155.  The liquid temperature is then determined by depressing one or two of the buttons 117.  A latch bar 129 co-operates with latch arms 121, 124 associated with the buttons 117 and 118a, 118b or 118c.  When the desired level is reached one of the switches 150a, 150b or 150c completes a circuit through a solenoid 133 which raises the latch bar 129 and releases all the buttons.  The liquid supply is cut off and the timer motor resumes operation, as indicated by the green light 114.  Shortly before the timer motor reaches zero the switch 108 is operated, thereby energizing a solenoid 146 to pull a finger 139 on a lever 142 down out of engagement with a collar 138 on the button 116. The button 116 is returned to its initial position thereby allowing the drain valve 155 to open.  About a minute later switch 109 is operated and the whistle 151 again sounds until the operator opens switch 112b.  Safety features.-The operator cannot turn on the liquid supply without closing the drain valve since the control valve 137 supplies the operating air to the water-control valves 169, 169a. Further, the drain valve cannot be held operated without setting the timer 107 because switch 108, being closed, would set up a possible circuit through solenoid 146 to hold the arm 139 out of engagement with the collar 138.  The liquid supply cannot be turned on without first setting a liquid level since if a liquid supply button 117 is operated before a liquid level button 118a, 118b or 118c, the circuit through switches 125a, 125b or 125c is unbroken and current goes through the left-hand contact of a switch 136 to the solenoid 133, preventing the latching of the liquid control valve.  The switch 136 is operated by an adjustable abutment screw 135 carried by a pivotally-mounted rockbar 134 which extends along the row of arms 121, 124 so as to be actuable by any one thereof.  A push-button switch 113 connected to the solenoid 133 allows operator release of any undesired setting of the buttons.