Abstract: In a gravimetric weighing hopper, an infeed chute on the fixed hopper frame and a removable annular wall supported by a load cell are formed with respective annular edges which are angled relative to their aligned axes or are correspondingly notched or otherwise have annular portions about at least approximately one-half of their respective annular extents which are spaced axially from their remaining annular extents to enable the removable cylindrical wall to be spaced in close surrounding relation to the feed chute during normal operation and also to be readily manipulated relative to the feed chute when necessary or desired to be removed from the hopper.

Abstract: In a thermoplastic material extrusion line having a melt extruder, a gear pump, and a die aligned with one another, the gear pump is supported on a hinged articulable arm for swinging movement into and out of operative disposition in alignment with the extruder to simplify realignment of the gear pump with the extruder and the die whenever it becomes necessary to remove the gear pump from the line for maintenance or service.