Dry cleaner

Abstract

According to the present invention, a highly safe dry cleaner is provided, which ensures safety without the danger of ignition in a drying process even if so-called microcomputer runaway occurs. The dry cleaner includes a relay sequence controlling circuit ( 71 ). The relay sequence controlling circuit ( 71 ) includes a serial connection of a first valve (V 27 ) to be controlled, a first switch ( 77 ) which controls the turn-on of the first valve (V 27 ) and a second contact ( 76 a ) provided in a second relay ( 76 ). A detection circuit ( 79 ) which controls the second contact ( 76 a ) is connected to the serial connection. Thus, the first valve (V 27 ) is maintained in an inactive state irrespective of a first switch turn-on control performed by a control section ( 81 ) until the detection circuit ( 79 ) performs a predetermined operation to turn on the second contact 76 a.

1 . A dry cleaner which performs a laundry washing process employing a flammable solvent, a liquid removing process and a drying process, the dry cleaner comprising:
 a treatment tub in which laundry is contained, and the washing process, the liquid removing process and the drying process are performed;   an air circulation duct through which air taken out of the treatment tub flows back to the treatment tub in a closed flow circuit in the drying process;   heating unit which heats the air flowing through the air circulation duct;   controller which controls operation of the heating unit to perform the drying process;   signal outputting unit which outputs a termination signal in response to completion of a predetermined liquid removing operation performed in the treatment tub; and   a safety circuit which maintains the heating unit in an inactive state irrespective of a control status of the controller unless the termination signal is outputted.   
   
   
       2 . The dry cleaner according to  claim 1 ,
 wherein the treatment tub includes:   a liquid-tight outer tub;   an inner tub rotatably provided in the outer tub and configured to be rotated to remove the solvent from the laundry contained therein by a centrifugal force; and   a drive motor which rotates the inner tub,   wherein the signal outputting unit includes a mechanism which outputs the termination signal after one of the inner tub and the drive motor is rotated at a rotation speed not lower than a predetermined rotation speed level for a predetermined rotation period.   
   
   
       3 . The dry cleaner according to  claim 2 , wherein the signal outputting unit includes:
 a switch which is turned on when the rotation speed of one of the inner tub and the drive motor is not less than the predetermined rotation speed level; and   a timer which starts time measurement in response to the turn-on of the switch to measure a switch turn-on time during which the switch is turned on and, when the switch turn-on time reaches a predetermined period, outputs the termination signal.   
   
   
       4 . The dry cleaner according to any of  claim 3 ,
 wherein the heating unit includes:   a heat exchanger which exchanges heat with the air flowing through the air circulation duct; and   steam supplying unit which supplies steam to the heat exchanger,   wherein the safety circuit is configured to prevent the steam from being supplied from the steam supplying unit to the heat exchanger to maintain the heating unit in the inactive state.   
   
   
       5 . The dry cleaner according to  claim 4 ,
 wherein the steam supplying unit includes:   a steam supplying passage through which the steam is supplied; and   a valve which opens and closes the steam supplying passage,   wherein the safety circuit is configured to constantly close the valve to maintain the heating unit in the inactive state.   
   
   
       6 . The dry cleaner according to  claim 5 ,
 wherein the steam supplying passage includes a plurality of steam supplying passages, and valves are respectively disposed in the steam supplying passages,   wherein the safety circuit is configured to constantly close a predetermined one of the valves to maintain the heating unit in the inactive state.   
   
   
       7 . The dry cleaner according to  claim 1 ,
 wherein the heating unit includes:   a heat exchanger which exchanges heat with the air flowing through the air circulation duct; and   steam supplying unit which supplies steam to the heat exchanger,   wherein the safety circuit is configured to prevent the steam from being supplied from the steam supplying unit to the heat exchanger to maintain the heating unit in the inactive state.   
   
   
       8 . The dry cleaner according to  claim 7 ,
 wherein the steam supplying unit includes:   a steam supplying passage through which the steam is supplied; and   a valve which opens and closes the steam supplying passage,   wherein the safety circuit is configured to constantly close the valve to maintain the heating unit in the inactive state.   
   
   
       9 . The dry cleaner according to  claim 8 ,
 wherein the steam supplying passage includes a plurality of steam supplying passages, and valves are respectively disposed in the steam supplying passages,   wherein the safety circuit is configured to constantly close a predetermined one of the valves to maintain the heating unit in the inactive state.   
   
   
       10 . A safety circuit for a dry cleaner, comprising:
 a switch which is turned on when a rotation speed of one of an inner tub for being rotated to remove solvent from a laundry contained therein by a centrifugal force and a drive motor for rotating the inner tub is not less than a predetermined rotation speed level; and   a timer which starts time measurement in response to the turn-on of the switch to measure a switch turn-on time during which the switch is turned on and, when the switch turn-on time reaches a predetermined period, outputs a termination signal.