Washing machine and liquid additive supply device for a washing machine

Abstract

Embodiments of the present invention provide a washing machine, having a drum configured to accommodate laundry, a water supply unit configured to supply water into the drum, and a liquid additive supply device configured to supply a liquid additive into the drum, where the liquid additive supply device includes a reservoir tank configured to store the liquid additive, and a floater installed in the reservoir tank and configured to float upward by a buoyant force to determine a fill-level of the liquid additive. The floater has a slanted portion having a width narrowing toward a top thereof to reduce a resistance of the liquid additive when the floater floats upward by the buoyant force.

What is claimed is: 
     
         1 . A washing machine comprising:
 a drum configured to hold laundry;   a water supply unit configured to supply water into the drum; and   a liquid additive supply device configured to supply a liquid additive into the drum,   wherein the liquid additive supply device comprises:
 a reservoir tank configured to hold liquid additive; and 
 a buoyant floater disposed in the reservoir tank and configured to float on a surface of the liquid additive, wherein a position of the buoyant floater indicates a fill-level of the liquid additive, and 
 wherein the buoyant floater comprises a slanted portion and a pointed top to reduce a resistance of the liquid additive when the buoyant floater floats upward. 
   
     
     
         2 . The washing machine of  claim 1 , wherein the reservoir tank comprises a first tank and a second tank, wherein the first tank is configured to hold a first type of liquid additive and comprises a first buoyant floater, and wherein the second tank is configured to accommodate a second kind of liquid additive and comprises a second buoyant floater. 
     
     
         3 . The washing machine of  claim 1 , wherein the buoyant floater comprises:
 a buoyant portion configured to generate a buoyant force;   a rotatable connecting arm coupled to the buoyant portion at a first side of the buoyant floater and coupled to one side of the reservoir tank by a hinge; and   a weight provided at a second side of the buoyant floater and configured to apply a load to the rotatable connecting arm, wherein the first side and the second side are opposite sides.   
     
     
         4 . The washing machine of  claim 3 , wherein the liquid additive supply device further comprises a sensing unit disposed on a side of the reservoir tank facing the buoyant portion, and configured to sense a proximity of the buoyant portion, and a magnetic member disposed inside of a lower portion of the buoyant portion and wherein the sensing unit is configured to detect the magnetic member. 
     
     
         5 . The washing machine of  claim 3 , wherein the buoyant portion covers 60% to 90% of a lower surface of the reservoir tank. 
     
     
         6 . The washing machine of  claim 3 , wherein the weight is fastened to the rotatable connecting arm by at least one of a screw and a bolt. 
     
     
         7 . The washing machine of  claim 4 , wherein the liquid additive supply device further comprises:
 a control unit configured to identify a shortage of liquid additive in response to a shortage signal transmitted from the sensing unit; and   a display unit configured to display an indication of the shortage of the liquid additive in response to a control signal transmitted from the control unit.   
     
     
         8 . The washing machine of  claim 1 , wherein the slanted portion comprises curved surfaces and wherein the buoyant floater comprises a streamlined vertical cross section. 
     
     
         9 . The washing machine of  claim 1 , wherein the slanted portion comprises flat surfaces and wherein the buoyant floater has a triangular vertical cross section. 
     
     
         10 . The washing machine of  claim 1 , wherein the slanted portion comprises curved surfaces with a round top end and wherein the buoyant floater has a semicircular vertical cross section. 
     
     
         11 . A liquid additive supply device, the device comprising:
 a removable reservoir tank disposed within an interior space of a detergent dispenser and configured to hold a liquid additive; and   a buoyant floater disposed on one side of a lower portion of the removable reservoir tank and configured to float upward to determine a fill-level of the liquid additive,   wherein the buoyant floater comprises a slanted portion having a width narrowing toward a top end of the slanted portion, wherein the slanted portion reduces a resistant force exerted on the buoyant floater by the liquid additive when the buoyant floater floats upward due to a buoyant force.   
     
     
         12 . The device of  claim 11 , wherein the removable reservoir tank comprises a first tank and a second tank, wherein the first tank and the second tank are configured to separately hold different kinds of liquid additives, wherein the first tank comprises a first buoyant floater, and wherein the second tank comprises a second buoyant floater. 
     
     
         13 . The device of  claim 11 , wherein the buoyant floater comprises:
 a buoyant portion configured to generate the buoyant force;   a rotatable connecting arm disposed on the buoyant portion and coupled to one side of the removable reservoir tank by a hinge; and   a weight disposed at an end of the rotatable connecting arm and configured to apply a load to the rotatable connecting arm.   
     
     
         14 . The device of  claim 13 , further comprising:
 a sensing unit disposed on one side of the removable reservoir tank facing the buoyant portion and configured to sense proximity of the buoyant portion; and   a magnetic member disposed inside the buoyant portion and configured to be detected by the sensing unit.   
     
     
         15 . The device of  claim 13 , wherein the buoyant portion covers 60% to 90% of a lower surface of the reservoir tank. 
     
     
         16 . The device of  claim 13 , wherein the weight is coupled to the rotatable connecting arm by at least one of a screw and a bolt. 
     
     
         17 . The device of  claim 11 , wherein the slanted portion comprises curved surfaces with at a pointed top end and wherein the buoyant floater has a streamlined vertical cross section. 
     
     
         18 . The device of  claim 11 , wherein the slanted portion comprises flat surfaces with at a pointed top end and wherein the buoyant floater has a triangular vertical cross section. 
     
     
         19 . The device of  claim 11 , wherein the slanted portion comprises curved surfaces with a round top end and wherein the buoyant floater has a semicircular vertical cross section.