| 摘要 |
<p>A pump 20 for pumping fluid, eg in High Pressure Liquid Chromatography (HPLC), comprises a pump head 200 comprises a piston assembly 204 reciprocating in a working chamber (400, fig.4) to thereby displace fluid, a pump base 202 accommodating a piston actuator 206 mechanically lockable to the piston assembly 204 in a working mode of the pump to thereby drive the piston assembly 204 to reciprocate. A locking/unlocking mechanism 208 is configured, upon unfastening the pump head 200 from the pump base 202, to mechanically unlock the piston actuator 206 from the piston assembly 204 in a maintenance mode of the pump. The mechanical locking mechanism 208 comprises a spring 212 which is compressed in the working mode and displaces a member 214 when the pump head 200 is unfastened from the pump base 202. The member 214 actuates a hook 244 on a lever member 216 having a further hook 218 which is thereby disengaged from an undercut 220 of the piston assembly 204.</p> |
