Patent ID: 9551338
Date: 2017-01-24
CPC Classifications: A61B,A61M,B29L,F04B,F16J

Claim:
1. A pump comprising: a barrel for holding fluid; a piston for drawing fluid into the barrel and driving fluid out of the barrel, wherein the piston comprises a plunger configured to move within the barrel and a sheath configured to move around an outer surface of the barrel; and a driving member; wherein an inner surface of the sheath and the outer surface of the barrel have complementary screw threads so that, in use, rotating the piston causes the piston to travel along the barrel; wherein the piston comprises an engagement section for engaging with the driving member and enabling the driving member to turn the piston, wherein the engagement section comprises a slot for engaging the driving member by relative motion between the piston and the driving member in a direction substantially perpendicular to the direction of travel of the piston along the barrel, and wherein the driving member is disengageable from the engagement section.