Sink drain

Abstract

A sink drain may include a drainage tube, a strainer, an O-shaped sealing pad, a drain cover, and a general bolt. The drainage tube has a blocking edge at an upper end thereof, and a thread nut is disposed on the drainage tube. The strainer has a cup-shaped main body, and a thread portion is formed on the outer periphery of a lower section of the main body. The thread nut of the drainage tube is engaged with the thread portion of the strainer to complete the connection between the drainage tube and the strainer. The sealing pad, which is elastically deformable, has a first section and a second section, and the first section having a larger diameter than the second section is located above the second section. The drain cover with a second O-ring is downwardly put in a second drainage hole of a sink.

What is claimed is: 
     
         1 . A sink drain comprising a drainage tube, a strainer, an O-shaped sealing pad, a drain cover, and a general bolt;
 wherein the drainage tube has a blocking edge at an upper end thereof, and a thread nut is disposed on the drainage tube from bottom to top; the blocking edge is configured to block and couple with the thread nut, and the thread nut is only rotatable when assembling and is not detachable from the upper end of the drainage tube, and a first O-ring arranged on the inner periphery of the thread nut is positioned on the upper end of the drainage tube;   wherein the strainer has a cup-shaped main body, and a thread portion is formed on the outer periphery of a lower section of the main body; the thread nut of the drainage tube is engaged with the thread portion of the strainer to complete the connection between the drainage tube and the strainer; the first O-ring is adapted to achieve the sealing effect between the main body and the drainage tube; a lock hole axially penetrates through the center of a bottom portion of the main body, and a plurality of axial first drainage holes are formed around the lock hole; a first connecting hole having a larger diameter than the main body is formed at an upper end of the main body;   wherein the sealing pad, which is elastically deformable, has a first section and a second section, and the first section having a larger diameter than the second section is located above the second section; the second section is inserted into the first connecting hole of the strainer, and the first section of the sealing pad is abutted against a bottom end of a sink when the sink drain installed; and   wherein the drain cover comprises a second connecting hole axially penetrating through the center thereof, and a plurality of axial filtering holes are formed around the second connecting hole, and a second O-ring is coupled on the drain cover; the drain cover with the second O-ring is downwardly put in a second drainage hole of the sink, and the general bolt is configured to pass through the second connecting hole and be downwardly screwed into the lock hole of the strainer; the strainer and the drain cover are installed on the sink, and the depth that the general bolt downwardly screws into the lock hole is arranged according to different thicknesses of the sinks such that the sink drain of the present invention is applied to the single-layer sink and the double-layer sink; the general bolt is screwed to drive the strainer to upwardly abut against the sealing pad, and the deformed sealing pad is configured to achieve the sealing effect on the bottom end of the sink and the drain cover.   
     
     
         2 . The sink drain of  claim 1 , wherein the upper end of the drainage tube is bent outwardly to form the blocking edge. 
     
     
         3 . The sink drain of  claim 1 , wherein the main body has a lower portion having a smaller diameter than the main body, and the thread portion is formed on the lower portion. 
     
     
         4 . The sink drain of  claim 1 , wherein the second connecting hole of the drain cover is a counterbore. 
     
     
         5 . The sink drain of  claim 1 , wherein a lower surface of the drain cover is connected to a peripheral edge to form the drain cover into a cap-nut shape.