Patent Publication Number: US-6341391-B1

Title: Hidden drain outlet structure for sink

Description:
FIELD OF THE INVENTION 
     This invention relates to an improved hidden drain outlet structure for sink and particularly a hidden drain outlet structure that may be disassembled easily for cleaning and repairs, and is capable of discharging water smoothly without clogging the drain pipe. 
     BACKGROUND OF THE INVENTION 
     The conventional drain outlet structure of a sink (as shown in FIG. 1) mostly has a control bar for lifting a plunger up or down when in use. The control bar sticks out from the drain pipe for a significant distance. The plunger head will be moved up above the basin bottom when draining water. It is easy to suck in foreign articles or garbage and block the drain pipe. The construction is rough and lacks aesthetic appealing. In view of these disadvantages, there are some refinements and improvements been developed. U.S. Pat. No. 5,509,150 (shown in FIG. 2) is one of the examples. It has a hidden drain feature which includes a drain pipe  10  connects with an outlet of the sink  1 . In the drain pipe  10 , there is a movable plunger  11  controlled by a pull rod  12  for moving up to drain water or moving down to retain water. At the top end of the pipe  10 , a stationary disk  13  is provided for trapping foreign articles and garbage. Although it has a more appealing look than the conventional drain features, it has some disadvantages. For instance, the stationary disk  13  is fixed and cannot be removed. If the drain pipe  10  is clogged, the whole set of the drain pipe  10  has to be disassembled from under for doing the repairs job. It is very inconvenient and time consuming. Furthermore, as water discharge always forms a vortex at the outlet, the substantially flat top of the stationary disk  13  significantly slows down water discharge speed. Its fixed stationary disk  13  design also cannot match with most filtering articles now available in the market place that are designed for conventional sinks and drain features. There is still room for improvement. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to provide an improved hidden drain outlet structure for sinks that has a drain head screwed to the upper end of a drain pipe. The drain head may engage with a filter which is easy to disassemble for repairs and maintenance. It is also capable of discharging water smoothly without clogging the drain pipe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, as well as its many advantages, may be further understood by the following detailed description and drawings, in which: 
     FIG. 1 is a schematic sectional view of a conventional drain feature for a sink. 
     FIG. 2 is another schematic sectional view of a conventional drain feature for a sink. 
     FIG. 3 is an exploded view of this invention. 
     FIG. 4 is a perspective of this invention. 
     FIG. 5 is a sectional view of this invention in use for retaining water. 
     FIG. 6 is a sectional view of this invention in use for draining water. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This invention aims at providing an improved hidden drain outlet structure for sinks that may be disassembled easily for cleaning and repairs, and is capable of discharging water smoothly, and is sturdily constructed and durable, and has aesthetic look and may be used safely. 
     Referring to FIGS. 3 and 4, the drain outlet structure according to this invention includes a drain pipe  2  which has drain passage  20  formed therein. At the upper section of the drain passage  20 , there is a neck section  21  which has a smaller diameter and has a slant inside wall (shown in FIG.  5 ). At one side of the drain pipe  2 , there is a control bar  22  run through the side wall of the drain pipe  2  and has one end disposed inside the drain passage  20  for engaging with a lower end of a plunger  23 . The plunger  23  is movable in the drain passage  20  and has a plunger flange  24  located at the top end. There is a seal ring  25  engages with the circumference of the plunger flange  24 . When the plunger  23  is moved downward, the plunger flange  24  and seal ring  25  will also be moved downward to engage with the neck section  21  to seal the drain outlet. The drain pipe  2  further has external screw threads  26  formed at the outer wall and an overflow outlet  27  formed at a selected location. Above the drain pipe  2 , there is a drain head  3  screwed with the top end of the drain pipe  2 . The drain head  3  is hollow and has a plurality of reinforced curved ribs  30  located inside. The ribs  30  join in the center to form a juncture which has an aperture  31  for holding a screw nut  32  therein. The drain head  3  further has internal screw threads  33  for engaging with the external screw threads  26  of the drain pipe  2 . The periphery of the drain head  3  forms an annular ring  34  which has an arched surface tilted slightly upward. The arched annular ring  34  and curved ribs  30  form a double curved sectional profile and form a valley in a middle section (shown in FIG.  5 ). 
     There is further a circular filter  4  located above the drain head  3 . The filter  4  forms like a disk which has a recess through hole  40  in the center for fastening to the screw nut  32  through a screw  43 . The filter  4  has a plurality of water-drop-shaped discharge slots  41  extended outward radially from the through hole  40 . At the outer periphery away from the slots  41 , the filter  4  has an annular rim  42  bent downwardly then to engage with the annular ring  34  of the drain head  3 . Thus form the completed assembly of this invention which may be disposed at the bottom of the sink and has a smooth surface for reducing water flow resistance. All the aforesaid elements may be made from plastics or metallic material. 
     Referring to FIG. 5, when this invention is in use, the drain pipe  2  is fastened to the bottom of the sink  1  (installation technique is known in the art and will be omitted herein). Move the control bar  22  downward, the plunger  23  will also be moved downward, the plunger flange  24  will engage with the slant inside wall of the neck section  21  to stop water from flowing down and water will be retained in the sink  1 . Referring to FIG. 6, when the control bar  22  is moved upward, the plunger  23  will be moved upward. The plunger flange  24  will be lifted and moved away from the neck section  21 , then water will be discharged out from the slots  41  of the filter  4  through the drain head  3  and drain passage  20 . 
     The structure of this invention has the following advantages: 
     1. The filter may trap and collect debris and other foreign articles such as hairs, contact lens, artificial tooth, ring or the like from flowing into the drain pipe and may prevent the drain pipe from clogging. 
     2. The filter is removable and may be replaced easily when damaged. Even if the drain pipe is clogged, the filter may be removed from the top end easily and to clear the clogged pipe conveniently. 
     3. The double curve shape of the filter and drain head enables forming discharging vortex for water flow to be drained quickly. 
     4. The filter and drain head engage snugly. The reinforced ribs further provide the filter additional support. Hence the filter may withstand more pressure without denting or damage. 
     5. The filter has a smooth rim to cover the slant annular ring of the drain head, and may prevent people from injury or hurting. 
     6. All the elements of this invention may be made from plastics or metallic material. They are relatively low costs and light weight, and are easy to carry for repairs and replacement. 
     7. The discharge slots in the filter may be made in various forms and sizes desired. It may add aesthetic appealing and to trap all kinds of foreign articles. 
     It may thus be seen that the objects of the present invention set forth herein, as well as those made apparent from the foregoing description, are efficiently attained. While the preferred embodiment of the invention has been set forth for purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.