(under subclass 294) Abrading machine wherein control of the rotary drive motion is by way of fluid pressure.
(1) Note. This subclass takes a patent related to a mechanism for imparting rotary motion to a tool by direct application of fluid pressure, as well as a device for governing the rotary motion of a tool by fluid resistance. Excluded from this subclass is a device which is indirectly actuated by fluid pressure such as a grinder rotated by a piston driven crankshaft.
