Means to create a vacuum or apply fluid pressure within a press forming mold:
(under the class definition) Apparatus comprising means utilizing differential fluid pressure to shape fluent or bulk material.
(1) Note. Using a fluid pressure to cause movement of a press member is excluded, and will be found in other subclasses, for example 43, 389+ and 457.
(2) Note. The fluid pressure may directly contact the work,
as in isostatic or hydrostatic shaping apparatus, or may effect shaping force to an intervening flexible pressure transmitting means which contacts the work, as in inflatable bag shaping apparatus.
SEE OR SEARCH THIS CLASS, SUBCLASS:
43, for a toroidal female shaping means combined with a fluid pressure actuated internal diaphragm for holding a preform against the female shaping means.
387.1+, for preform reshaping means by contacting work directly with fluid.
389+, for preform reshaping means by a fluid pressure actuated flexible diaphragm. 406+, for apparatus comprising press members which may be caused to move by hydraulic or other fluid pressure, and especially subclass 417 for an expansible male shaping member.
437+, for a shaping surface having means for ejecting the work with a differential gas.
