Liquid delivery pump for liquid chromatograph

Abstract

A liquid delivery pump includes a pump room for transferring liquid, a plunger having one end located in the pump room for moving reciprocally therein for delivering the liquid in the pump room, and a base end, and a crosshead for reciprocal movement situated adjacent to the pump room and having a flat end surface. A ball is attached to the crosshead to contact the flat end surface thereof. The base end is attached to the crosshead so that the plunger rotates freely relative to the flat end surface through the ball.

1 . A liquid delivery pump for a liquid chromatograph, comprising: 
 a pump room for transferring liquid,    a plunger having one end located in the pump room for moving reciprocally therein for delivering the liquid in the pump room, and a base end,    a crosshead for reciprocal movement situated adjacent to the pump room and having a flat end surface, and    a ball attached to the crosshead to contact the flat end surface thereof, said base end being attached to the crosshead so that the plunger rotates freely relative to the flat end surface through the ball.    
   
   
       2 . A liquid delivery pump according to  claim 1 , further comprising sealing means attached to the pump room, through which the plunger passes, and a cam for reciprocally moving the crosshead.  
   
   
       3 . A liquid delivery pump according to  claim 2 , wherein said base portion of the plunger is screwed into the ball.