Laundry treating device and method for its operation

Abstract

A laundry treating device such as a washing machine has a rotatable drum having a circumferential drum wall for placing the laundry in, a drive motor for the drum, a power control unit for supplying a drive current to the drive motor, current sensor means for supervising the drive current supplied to the drive motor, rotation position sensor means for supervising a rotation position of the drum and at least one protrusion on an inside of the circumferential drum wall. The protrusion is variable and flexible in its height over the inside of the circumferential drum wall and in its outer shape. Actuation means are provided for effecting a change of height and shape of the protrusion. Various curves for the current with varying shape of the protrusions may be recorded and compared with pre-stored reference curves for different types of laundry from various fibers.

1 . A laundry treating device having:
 a rotatable drum having a circumferential drum wall for placing laundry in,   a drive motor for said rotatable drum,   a power control unit for supplying a drive current to said drive motor,   current sensor means for supervising said drive current supplied to said drive motor,   rotation position sensor means for supervising a rotation position of said drum,   at least one protrusion on an inside of a circumferential drum wall of said rotatable drum,   wherein   said protrusion is variable or movable or flexible in its height over said inside of said circumferential drum wall, or   said protrusion is variable or movable or flexible in its outer shape,   actuation means are provided for effecting a change of height or shape of said protrusion.   
     
     
         2 . The laundry treating device according to  claim 1 , wherein said laundry treating device is a washing machine or a laundry dryer. 
     
     
         3 . Device according to  claim 1 , wherein a device control is provided having a processing means for calculating a rotation position of said drum or for calculating a drive current from said respective sensor means, wherein said processing means is adapted to calculate a load or a weight of laundry in said drum or a major fibre portion of said laundry. 
     
     
         4 . Device according to  claim 3 , wherein said processing means is adapted to calculate said load or said weight of said laundry in said drum or said major fibre portion of said laundry for adapting parameters of a further laundry treating procedure to said detected load or said detected major fibre portion, wherein said parameters are with regard to a temperature of water, a rotation speed of said drum or a shape of said at least one protrusion. 
     
     
         5 . Device according to  claim 3 , wherein in said processing means a storage is provided in which various groups of diagrams are stored being representative of a dependency of said drive current of said load in said drum as well as of said major fibre portion of said laundry. 
     
     
         6 . Device according to  claim 1 , wherein said actuation means for changing said height or said shape of said at least one protrusion is a passive actuation device with a temperature dependent shape changing material in a form of a spring or a lather or a rod. 
     
     
         7 . Device according to  claim 6 , wherein said actuation device is shape variable such that a first shape is present at a temperature below 30° C. and that a second shape is present at a temperature above 30° C. 
     
     
         8 . Device according to  claim 7 , wherein a third shape is present above 40° C. 
     
     
         9 . Device according to  claim 1 , wherein said temperature dependent shape changing material of said actuation means is inductively heatable and made from ferromagnetic material. 
     
     
         10 . Device according to  claim 9 , wherein outside of said drum an induction heating device is fixedly positioned being placed so as for said actuation device to pass by radially inward of said induction heating device. 
     
     
         11 . Device according to  claim 1 , wherein said at least one protrusion is made from elastic and flexible material in a form of a trough with two longitudinal end edges, wherein said protrusion is fixed to said inside of said drum with said two end edges such that in an initial state of said protrusion, said protrusion has a certain initial height and a certain initial profile, wherein in at least one further state of said protrusion said height is diminished and said protrusion is flexed laterally to a side along a circumferential direction of said drum. 
     
     
         12 . Device according to  claim 11 , wherein in an initial state of said protrusion, said protrusion is symmetrical in its profile when viewed from a side, wherein in at least one further state of said protrusion, said protrusion is flexed laterally to a side for between 1 cm and 3 cm. 
     
     
         13 . Method for operating a laundry treating device according to  claim 1 , wherein:
 in a first step, various reference curves for said drive current are recorded with a variation of one variable of the group of: shape of said protrusion, drum rotation speed, drum rotation direction, weight of said laundry, typical size of pieces of laundry, major fibre portion of said laundry,   wherein for each reference curve only one of said variables is being varied, wherein said other variables are being held constant,   said reference curves are being stored,   in a second step, when laundry is put into said drum and is actually about to be treated, testing is performed as said second step before starting said treatment of said laundry by varying at least one parameter of the group of: shape of said protrusion, drum rotation speed, drum rotation direction, whereinafter a comparison is made with said various reference curves stored in said storage to determine at least one variable of the group of: weight of said laundry, typical size of pieces of laundry, major fibre portion of said laundry,   in a third step, actual treatment of said laundry in said laundry treating device is adapted to said weight of the laundry, said typical size of pieces of laundry and/or said major fibre portion of said laundry.   
     
     
         14 . Method according to  claim 13 , wherein said reference curves are being stored in a storage of a processing means of a device control. 
     
     
         15 . Method according to  claim 13 , wherein variables of said laundry treating process are adapted to a kind of laundry or to said major fibre portion of said laundry by varying a temperature of water added to said laundry process or varying a rotation speed of said drum or varying said shape of said protrusion. 
     
     
         16 . Method according to  claim 13 , wherein by supervising said drive current supplied to said drive motor a force is measured when pieces of laundry slide down in said drum along an inside of said circumferential drum wall while said drum is rotating. 
     
     
         17 . Method according to  claim 13 , wherein in addition to measuring a force or said current supplied to said drive motor, respectively, said position of said at least one protrusion is determined and taken into account by reading out information of said rotation position sensor means. 
     
     
         18 . Method according to  claim 13 , wherein additional information input is received by a water level sensor or by a water amount sensor in said drum or by a temperature sensor for said water temperature. 
     
     
         19 . Method according to  claim 13 , wherein varying said shape of said protrusion in said first step or in said second step includes flexing said protrusion from a maximum into one direction along the circumferential direction of said drum to a maximum into an opposite direction along said circumferential direction of said drum. 
     
     
         20 . Method according to  claim 19 , wherein said flexing between said two maxima is being made in at least two or three steps.