(under the class definition) Apparatus in which some portion of the mechanism is useful only and thereby requires in its normal operation that the walls of the dispenser or receiver be distortable or capable of being pushed out of one position into another except as a mere incident to affixing the receiver to the filling head. Pre-shaping of the receiver prior to placing same on the filling head is here included.
(1) Note. Examples of such essential flexibility or yielding character are automatic control of a filling operation by expansion of the receiver being filled and excess material removal by contraction of the receiver, and delivery of contents material by collapsing walls of the supply container.
(2) Note. Motion of a foldable flap about its hinge line being analogous to the motion of other closure elements, is not included in this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
154, for successive receiver type filling systems in which the receivers have flap closed inlets, see (2) Note.
166, for successive receiver type filling systems for bags or similar receivers. 312, for expansible centering or holding means for receivers which may or may not be of the bag type.
313, for miscellaneous flexible or collapsible receiver coacting means in filling devices.
314+, for bag or liner securing means in filling systems.
350, for coupling controlled receiver inlet flow in which the inlet has an externally engaged flap or closure member.
SEE OR SEARCH CLASS
53, Package Making,
570+, for a packaging machine for forming and filling a bag, subclasses 373.3+ for closing a package or filled receptacle by means adapted to engage a closure flap, and subclasses 381.1+ for package making including means to open or erect a receptacle.
