F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
F15B11/18—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors used in combination for obtaining stepwise operation of a single controlled member