Variable flow fluid pump

Abstract

A pump assembly including a resilient dome attached to a base plate, which together define a chamber. A flapper, supported on a raised center boss on the base plate, seats against a raised annular valve seat to selectively expose fluid inlet apertures in the base plate. The dome has a one-way fluid outlet valve. Dome compression seals the flapper against the valve seat and expels fluid through the fluid outlet valve. Release of the dome allows the outlet valve to close, and the dome regain its original shape, thereby creating a vacuum force that unseats the flapper and draws fluid into the chamber via the fluid inlet apertures. The pump assembly can be made for a variety of fluid densities and viscosities by varying the material and thickness of the flapper, the heights of the valve seat and the center boss, and the size and number of the fluid inlet apertures.

1 . A fluid pump comprising: 
 a dome having a flange;    a base plate secured to the flange at a periphery of the base plate;    the base plate including a flapper mount for receiving a central portion of a flapper;    the base including a valve seat for engaging a peripheral portion of the flapper to form a fluid seal;    the base plate including an inlet aperture positioned beneath the flapper; and    an outlet valve in fluid communication with the dome.    
   
   
       2 . The fluid pump of  claim 1  wherein: 
 the flapper mount is positioned on a raised boss extending from the base plate.    
   
   
       3 . The fluid pump of  claim 1  wherein: 
 a height of boss versus a height of valve seat is set to control fluid flow through the pump.    
   
   
       4 . The fluid pump of  claim 1  wherein: 
 the inlet aperture includes a plurality of inlet apertures.    
   
   
       5 . The fluid pump of  claim 4  wherein: 
 the size and number of inlet apertures is set to control fluid flow through pump.    
   
   
       6 . The fluid pump of  claim 1  wherein: 
 dome is made from a low durometer thermoplastic material    
   
   
       7 . The fluid pump of  claim 1  wherein: 
 the dome is substantially hemispherical.    
   
   
       8 . The fluid pump of  claim 1  further comprising: 
 a flapper mount extending up from the boss, the flapper mount receiving the flapper.