| 摘要 |
A pump 1 comprising a cylinder 2, a piston 3 disposed in said cylinder 2 and moveable along a stroke axis therein in a priming direction and in a dispensing direction, a spring means 4 biasing said piston 3 to move in said priming direction, and a retention member 5 limiting movement of said piston 3 in said priming direction beyond an end point. The retention member 5 is mounted on a support member 6 and is movable thereon between a first position in which said end point determines a first cylinder capacity and at least one further position in which said end point determines a second cylinder capacity. The support member 6 my take the form of a ring having internal screw thread 44 which engages an external screw thread 46 on the retention member 5. Rotation of the support member 6 drives the retention member in either direction relative to it. The support member may be retained by clips 34, such that it can be released to allow the pump 1 to be used at maximum capacity for priming before being returned to its reduced capacity setting by re-attaching the support member 6. |
