| 摘要 |
<p>A fluid-driven proportioning pump (10) dispenses precise volumes of three fluids, includes a drive cylinder (12) housing a drive piston (40) which divides drive cylinder (12) into drive fluid chambers (106, 108). From each face of drive piston (40) projects two proportioning pistons (50, 52, 54, 58) which extend into proportioning cylinders (42, 44, 46, 48). An over-center mechanism triggered by movement of drive piston (40) at the extremes of its reciprocating motion operates valving (62) which admits pressurized drive fluid into alternate of drive fluid chambers (106, 108). The over-center mechanism is activated by C-shaped springs (68, 70), and is housed within drive cylinder (12). Selective adjustment is possible of the proportion among the drive fluid and other constituent fluids. Each proportioning piston (50, 52, 54, 58) is a disk-like piston head (116) slidably mounted on a turnable shaft (114) that projects from the face of the drive piston (40). The enlarged head (128) of the turnable shaft (114) is provided with a fitting (128) manipulatable from outside the pump by a retractable tool (132).</p> |
