PNEUMATIC DEVICE HAVING A SELECTIVELY VARIABLE ORIFICE

摘要

A pneumatic device (24) having a selectively variable pneumatic output comprises an inlet connectable to an air source and an outlet disposed in a flow path, a control assembly in the flow path and having a plurality of differently sized primary orifi (28a-28h) . The control assembly includes a selector (30) having a secondary orifice (39) , the selector moveable relative to the primary orifi between a plurality of positions, the primary orifi and the secondary orifice arrangeable relative to one another to permit the secondary orifice to be in flow communication with a selected one of the primary orifi. The control assembly further blocks the remaining primary orifi when the secondary orifice is aligned with the selected one of the primary orifi .