Pump

Abstract

A pump is capable of screening out coarse contaminants from fluid, and includes a pump housing with a fluid-entering portion and a fluid-exiting portion, a screen unit mounted on the fluid-entering portion and having holes for screening out the coarse contaminants from the fluid, and a filter unit mounted on the fluid-exiting portion and having holes for filtering out fine contaminants from the fluid. The holes of the screen unit are larger than the holes of the filter unit.

1 . A pump capable of screening out coarse contaminants from fluid, said pump comprising: 
 a pump housing including a fluid-entering portion and a fluid-exiting portion;    a screen unit mounted on said fluid-entering portion and having holes for screening out the coarse contaminants from the fluid; and    a filter unit mounted on said fluid-exiting portion and having holes for filtering out fine contaminants from the fluid,    wherein said holes of said screen unit are larger than said holes of said filter unit.    
   
   
       2 . The pump as claimed in  claim 1 , wherein said fluid-entering portion includes a first tubular wall which has a first end connected to said pump housing and a second end extending away from said pump housing, and a first inlet port projecting from said first tubular wall between said first and second ends.  
   
   
       3 . The pump as claimed in  claim 2 , wherein said screen unit includes a second tubular wall surrounded by said first tubular wall, a second inlet port projecting toward said first inlet port from said second tubular wall, and an end wall connected to said second tubular wall proximate to said first end of said first tubular wall, said holes of said screen unit being formed in said second tubular wall and said end wall.  
   
   
       4 . The pump as claimed in  claim 3 , wherein said fluid-entering portion further includes a first opening formed at said second end of said first tubular wall, said screen unit further having a second opening opposite to said end wall.  
   
   
       5 . The pump as claimed in  claim 4 , wherein said second tubular wall has a rim which projects outward and around said second tubular wall proximate to said second opening, said rim being seated on said second end of said first tubular wall.  
   
   
       6 . The pump as claimed in  claim 4 , wherein said fluid-entering portion further includes a cover removably covering said first opening.  
   
   
       7 . The pump as claimed in  claim 6 , wherein said cover is transparent.  
   
   
       8 . The pump as claimed in  claim 4 , wherein said screen unit further has a handle pivotally mounted on said second tubular wall proximate to said second opening.