Liquid pump

Abstract

The liquid pump has a pressure vessel with end-openings for hermetically holding liquid therein. The liquid flows from one of the end-openings to the other end-opening by utilizing a difference in a coefficient of thermal expansion of the pressure vessel and the liquid caused by heating or cooling the pressure vessel and the liquid together. The pressure vessel is a tube having an inner diameter of about 0.5 mm or less and a length of about 10 m or more.

We claim:  
     
         1 . A liquid pump comprising a pressure vessel with end-openings for hermetically holding a liquid therein, wherein the liquid flows from one of the end-openings to the other end-opening by utilizing a difference in a coefficient of thermal expansion of the pressure vessel and the liquid caused by heating or cooling the pressure vessel and the liquid together.  
     
     
         2 . The liquid pump according to  claim 1  further comprising a heating-cooling bath for receiving the pressure vessel having sufficient heat conductibility.  
     
     
         3 . The liquid pump according to  claim 1 , wherein the pressure vessel generates heat by voltage and the heating is conducted by applying voltage to the pressure vessel.  
     
     
         4 . The liquid pump according to  claim 1 , wherein the pressure vessel is a tube having an inner diameter of about 0.5 mm or less and a length of about 10 m or more.  
     
     
         5 . The liquid pump according to  claim 2 , wherein the pressure vessel is a tube having an inner diameter of about 0.5 mm or less and a length of about 10 m or more.  
     
     
         6 . The liquid pump according to  claim 3 , wherein the pressure vessel is a tube having an inner diameter of about 0.5 mm or less and a length of about 10 m or more.  
     
     
         7 . The liquid pump according to  claim 2 , wherein the heating-cooling bath is any one of an air bath and a liquid bath.