摘要 |
A diaphragm pump (10) including a body (11) that provides a pair of opposed pump chambers (12) and (13). Mounted in the body (11) is a piston assembly (14) providing a pair of pistons (15) joined by a transverse piston rod (16) so that the pistons (15) are caused to reciprocate in unison linearly in the direction (17) along the axis (18). Each piston (15) includes a diaphragm (22) that provides a first sub-chamber (23) and a second sub-chamber (24). A working fluid (liquid or gas) under pressure is alternately delivered to the sub-chambers (23) to cause the piston assembly (14) to reciprocate. A valve (25) is operated to co-ordinate delivery of the fluid under pressure or alternately to the first sub-chambers (23). |