Abstract: A centrifugal jig has a container mounted for rotation about its longitudinal axis (22), separated into an axial region (32) and a peripheral region by ragging material (41) supported by a screen (30). The peripheral region is composed of a series of hutch chambers (34) with reciprocating wall portions (45) located radially outside the screen (30), for repetitively dilating the ragging. Also disclosed is a hutch chamber construction applicable to both rotary and non-rotary jigs, having a reciprocating wall portion (45) which includes convergent wall surfaces leading to the hutch chamber concentrate outlet (44).

Abstract: A hinge assembly includes a first member having a curved-shape abutment surface spaced about a pivot axis, and a second member having a second abutment, which is a complementary shape to the first abutment surface. A link connects the members in a manner such that articulate movement is enabled while preventing human fingers or other objects being pinched between the abutment surfaces. A primary application of such a hinge is in a sectional door which is formed of a plurality of elongate panels having abutment surfaces. A method of forming the hinge and the door panels and a method of assembling such a sectional door are also disclosed.