| 20110274563 | DOSING PUMP - A dosing pump comprises an inlet for a solvent, an injection device for an additive, a reciprocating main piston for mixing the solvent with the additive during a suction stroke and for discharging the mixture from an outlet in an evacuation stroke. A divider substantially perpendicular to a rod connected to the main piston separates a main piston housing from a switching device for controlling a main piston stroke direction. The switching device comprises two inlet rotary valve assemblies that are disposed externally to a corresponding inlet aperture bored in the divider when in an opened state and are rotatable about an axis substantially perpendicular to the axis of the main piston. Each of the valve assemblies alternately opens and occludes a corresponding inlet aperture so that solvent flowing through a first inlet aperture performs a suction stroke and solvent flowing through a second inlet aperture performs an evacuation stroke. | 11-10-2011 |
