Patent Publication Number: US-6219861-B1

Title: Drain structure for a sink

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to sinks and more particularly to an improved drain structure for a sink or basin which includes a valve in the tube drain to control discharging the water from the sink. 
     Typical sinks or basins  10  comprise a drain port  11  connected to a drain pipe  12  and a chain  13  connected with a stronger  14  which is used to block up the drain port  11  to receive the water and is extracted out of the drain port  11  to discharge the water from the sink  10 . Another type of sink has a lift lever rod on top of the sink to control the operation of a pop-up stopper. This life rod is usually arranged together with the spout system and is structurally complicated and unpleasant to look at, especially for a high class sink. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention has a main object to provide an improved drain structure for a sink which is simple and ready to operate. 
     Another object of the present invention is to provide an improved drain structure for a sink which is pleasant to look at and especially suits to a high class metal sink. 
     Accordingly, the improved drain structure of the present invention comprises generally a valve secured into a drain port of a sink and a sliding stopper disposed in the valve and operated by finger press. It is supposed that when a first press is applied on the stopper, it will slide downward to discharge the water from the sink. If a second press is applied on the stopper, it will jump upward to stop the discharging of the water. 
     The present invention will become more fully understood by reference to the following detailed description thereof when read in conjunction with the attached drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a water sink according to the prior art, 
     FIG. 2 is an exploded perspective view to show the drain structure of the preferred embodiment according to the present invention, 
     FIG. 3 is a sectional view to show an assembly of FIG. 2, 
     FIG. 4 is a sectional view of FIG. 2 from a lateral side of the valve, 
     FIG. 5 is a sectional view of FIG. 3 while the stopper is pressed to slide downward, 
     FIG. 6 is a sectional view while the water discharging is stopped, 
     FIG. 7 is a sectional view from a lateral side of FIG. 6, and 
     FIG. 8 is a sectional view to show the valve is secured into the drain port of a sink. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIGS. 2,  3  and  8  of the drawings, the drain structure of the present invention comprises generally a drain structure  30  axially secured to a tube drain  21  of a sink or basin  20 . 
     The drain structure  30  includes a tubular valve seat  31 , a first circular fastener  34 , a tubular sleeve  32 , a slider  33 , a U-shaped positioning rod  36 , a circular button  37  and a second circular fastener  35 . The tubular valve seat  31  has a first threaded outer periphery  311  insertable into a drain pipe  22 , a second threaded outer periphery  212  on a narrowed protrudent opening  314  on the top thereof, a plurality of spaced water inlets  313  formed in the periphery of the opening  314  beneath the second threaded outer periphery  312 , a first annular flange  318  extending outward from the periphery thereof beneath the water inlets  313  and a shoulder  315  formed at a center of the tubular valve seat  31  to define a pair of arcuate water passages  316 . The shoulder  315  includes a first threaded central bore  317 . The first circular fastener  34  has a second threaded central bore  341  engageable with the first threaded outer periphery  311  of the tubular valve seat  31  and a hexagon configuration  342  on its underside for fastening the fastener on the valve seat  31 . The tubular sleeve  32  has a third threaded outer periphery  321  engaged with the first threaded center bore  317  of the valve seat  31  and a narrowed projection  322  extending downward from the bottom which has a lateral indentation  323  communicating to the inside of the sleeve  32 . The projection  322  includes a transverse retaining hole  3231  in an inner wall thereof, an annular depression  324  in an outer periphery beneath the third threaded outer periphery  321  and a longitudinal screw hole  329  (as shown in FIG.  4 ). A second annular flange  325  extends outwardly from an outer periphery of the sleeve  32  above the third threaded outer periphery  321  and a transverse screw hole  326  extends through an upper periphery. A screw  327  engages in the transverse screw hole  326 . A circular through hole  328  extends through the sleeve  32  in a position above the second annular flange  325 . The U-shaped positioning rod  36  is disposed in the sleeve  32  and has a first transverse end  361  engaging the transverse retaining hole  3231  of the indentation  323  and a second transverse end  362  on the top. The transverse end  361  is secured in position by a band  363  which may be any other packing means. A screw  364  engages the longitudinal screw hole  329  with a part of its shank projected upward inside the sleeve  32  for securing the lower end of a spring  365  thereon. The slider  33  is slidably disposed in the sleeve  32  and is biased by the spring  365 . The slider has a double V-shaped slot  331  in a lateral side. The second transverse end  362  of the U-shaped positioning rod  36  engages the slot  331 . A longitudinal slot  332  extends along a lateral side of the slider  33  at a position perpendicular to the position of the double V-shaped slot  331  and is slidably engaged with the shank of the screw  327  inside the sleeve  32  to prevent any lateral rotation of the slider  33 . 
     A threaded cylindrical protrusion  333  projects centrally upward from the top of the slider  33 . The circular button  37  axially engages the top of the slider  33  with a first sealing ring  374  and a washer  375  disposed therebetween. The button  37  has a third annular flange  371  extending outwardly from an outer periphery, a circular projection  372  projecting centrally downward from the underside thereof beneath the flange  371 . A third threaded central bore  373  is disposed in the bottom of the button  37  and is engaged with the threaded cylindrical protrusion  333  of the slider  33 . A second circular fastener  35  has a third threaded inner periphery  351  engageable with the second threaded outer periphery  312  of the valve seat  31  and a central hole  352  engageable with the button  37 . 
     To install the device, first sealing ring  319  is sleeved on the valve seat  31  from the underside thereof and the valve seat  31  is disposed axially into the tube drain  21  of the sink  20  with the first annular flange  318  stopped against the upper rim of the tube drain  21  and with the second sealing ring  319  engaged therebetween. The third sealing ring  343  is then sleeved on the valve seat  31  from the underside of the tube drain and then the first circular fastener  34  is tightened on the valve seat  31  by means of a wrench until the third sealing ring  343  completely closes the underside of the tube drain  21 . Finally, the second circular fastener  35  is fastened onto the protrudent opening  314  of the valve seat  31 . The button  37  is engaged in the central hole  352  of the fastener  35  and stopped by its own flange  371  against the underside of the fastener  35  such that a gap is defined between the second circular fastener and the first annular flange  318  of the valve seat  31  (as shown in FIGS.  3  and  4 ). 
     Referring to FIGS. 3 and 4 again, when the button  37  remains in the central hole  352  of the second annular fastener  35 , the slider  33  is positioned at an uppermost position because of the resilience of the spring  365  and the second transverse end  362  of the U-shaped positioning rod  36  is engaged with a lower stopping position  3314  of the double V-shaped slot  331 . So water inside the sink  20  is permitted to be discharged through the inlets  313  and the outlets  316  of the valve seat  31 . 
     Referring to FIGS. 5,  6  and  7 , when the button  37  is pressed downward a certain span, the slider  33  slides downward so that the second transverse end of the U-shaped positioning rod  36  slides upward along the double V-shaped slot  331  and temporarily stops at one of the two rest points  3312  or  3313  which are located above an upper stopping position  3311 . When the button  37  is released, the slider  33  will slide a small span upward due to the resilience of the spring  365  so that the second transverse end  362  of the U-shaped positioning slot  36  engages with the upper stopping position  3311  of the double V-shaped slot  331 . Therefore, water flow through the valve seat  31  is blocked by the flange  371  and sealing ring  374  to prevent water from discharging out of the valve seat  31  even with the water inlets  313  being open. Pressing on the button  37  again, the second transverse end  362  of the U-shaped positioning rod  36  will slide down via one of the rest points  3312  or  3313  and stops at the lower stopping position  3314 . Therefore, the button  37  returns to its original position to permit water to be discharged through the arcuate water passages  316  and the valve seat  31 . 
     Based on the above arrangement, the drain structure of the present invention provides a ready operation and meat outlook without requiring a lift rod or a stopper with a chain. 
     The specification relating to the above embodiment should be construed as exemplary rather than as limitative of the present invention, with many variations and modifications being readily attainable by a person of average skill in the art without departing from the spirit or scope thereof as defined by the appended claims and their legal equivalents.