with helical teeth, e.g. chevron-shaped, screw type

Full Title

Rotary-piston pumps specially adapted for elastic fluids > of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing > of other than internal-axis type > with toothed rotary pistons > with helical teeth, e.g. chevron-shaped, screw type

Classification Context

Section:

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Class:

POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS

Subclass:

ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS