摘要 |
<p>With reference to FIG. 3, the present invention provides a fluid injector (10) which functions as a positive displacement pump and comprises: a housing (12) in which a piston chamber is formed; a piston (11) which reciprocates in the piston chamber to define therewith a variable volume fluid pumping chamber; a one-way inlet valve (32) which allows flow of fluid into the pumping chamber from a fluid inlet; and a one-way outlet valve (25, 26, 27, 28, 29) which allows flow of fluid out of the pumping chamber to a fluid outlet (31). In operation of the injector the piston (11) cyclically moves to increase volume of the pumping chamber and draw fluid into the pumping chamber via the one-way inlet valve (32) and then the piston moves to decrease volume of the pumping chamber and expel fluid from the pumping chamber via the one-way outlet valve (25, 26, 27, 28, 29).</p> |