Hand pump for pumping fluid

Abstract

A hand operable pump device for pumping fluids includes a hollow body and an oval piston. The hollow body includes an inlet port and an outlet port. The inlet port is provided with a one-way valve permitting fluid flow into the pump. The outlet port is provided with a one-way valve permitting fluid flow out of the pump. The oval piston is designed to be pressed inwardly from an initial position by the hand, decreasing the volume of an oval chamber with a corresponding oval cross-section. The chamber is located within the pump and is fluidically connected with the inlet and outlet ports. The oval piston is further designed to return to the initial position when released, increasing the volume of the chamber.

1 . A hand operable pump device for pumping fluids comprising:
 a hollow body, with an inlet port and an outlet port, the inlet port provided with a one-way valve permitting fluid flow into the pump and the outlet port provided with a one-way valve permitting fluid flow out of the pump;   an oval piston designed to be pressed inwardly from an initial position by the hand, decreasing the volume of an oval chamber with a corresponding oval cross-section, the chamber being located within the pump and fluidically connected with the inlet and outlet ports, and to return to the initial position when released, increasing the volume of the chamber.   
     
     
         2 . A device as claimed in  claim 1 , wherein the inlet and outlet ports are located along the long axis of the oval cross-section. 
     
     
         3 . A device as claimed in  claim 1 , wherein the one-way valves comprise flapper valves. 
     
     
         4 . A device as claimed in  claim 3 , wherein the flapper valves comprise umbrella valves. 
     
     
         5 . A device as claimed in  claim 1 , wherein the inlet and outlet ports are each connected to a tube. 
     
     
         6 . A device as claimed in  claim 1 , wherein the piston is a spring operated piston. 
     
     
         7 . A device as claimed in  claim 1 , wherein the body comprises a cylinder with oval cross-section which is provided with a hinged cover pivotally attached to the body for pressing the piston. 
     
     
         8 . A device as claimed in  claim 7 , wherein the piston includes a domed surface and the cover includes a corresponding concave surface. 
     
     
         9 . A device as claimed in  claim 7 , provided with a latch to lock the cover at a closed position with the piston pressed inwardly. 
     
     
         10 . A device as claimed in  claim 9 , wherein the latch comprises a pivotable hook. 
     
     
         11 . A device as claimed in  claim 1 , wherein the piston includes an inner surface which defines with an opposite surface of the chamber a void, allowing flow of fluid through the pump even when the piston is fully pressed inwardly.