Abstract: A self-opening cuff comprising a fixed member, to which a cylindrically curved cuff is pivoted for swinging movement in a vertical plane. The fixed member is rigidly attached to the crutch tubing, and has two laterally projecting, angularly spaced side arms with an included angle of approximately 90.degree. between them. The two side arms have a cylindrically curved inner surface with the same radius of curvature as the cuff, and this curved surface is interrupted at its midpoint by a vertical slot. Disposed within the slot and swingably connected to the fixed member by a pivot bolt is a lug which is provided on the outside of the cuff. The top portion of the cylindrically curved surface is smoothly rounded with a curvature having its center at the pivot bolt axis, forming a ramp that the outer surface of the cuff rides on as it swings upwardly.

Abstract: A non-pneumatic tire for mounting on a rim having axially spaced annular mounting flanges. The tire is formed with a radially exterior tread surface having axially outwardly sloped side walls projecting radially inwardly therefrom and formed on their radially inwardly extremities with shoulders that nest against the radially outward edges of the mounting flanges. Retaining flanges then project radially inwardly therefrom for retention on the axially inner sides of the mounting flanges. The tread surface and opposite side walls cooperate to form a circumferential interior cavity which a latticework of webbing formed by axially extending interrupter webs which are spaced equidistance about such cavity and have an annular projecting circumferentially thereabout and connected with such axially projecting interrupter webs.

Abstract: A static mixer for streams of flowing materials comprises a flow passage defined in a laminated body having end plates and a number of intermediate plates all detachably interconnected to form a unitary structure. The flow passage follows a serpentine path, crossing and recrossing boundaries between the several plates. Mixing structures are formed in the passage for combining, dividing and recombining streams of flowing materials in the passage by means of rotation of flow path and altering the cross-sectional shape of the flow paths. Disassembly of the several plates of the laminated body permits easy access to individual sections of the flow passage to facilitate cleaning and repair. Flow passage sections extend along a path that bends about an axis perpendicular to the direction of flow therein to facilitate mixing and to achieve curvature of the path to enable it is cross and recross the several boundary surfaces between adjacent plates and the laminated body.