Abstract: An improved magnetorheological fluid damper is provided which effectively provides a smooth transition, without a sharp break in the damper force/velocity curve, between very low damping forces near zero damper velocity to higher damping forces at higher piston velocities while maintaining desirable maximum force levels. The damper includes a piston assembly, including a magnet assembly and a flow gap extending through the piston assembly to permit fluid flow between the chambers. The force/velocity optimization feature includes a groove or passage open to the flow gap, positioned in series with a part of the flow gap in a magnetic circuit generated by the magnet assembly and dimnensioned/sized to permit fluid flowing through the passage to experience a magnetorheological effect less than a magnetorheological effect experienced by fluid flowing through the flow gap but not through the groove. Preferably, the passage is formed in an inner annular surface of a flux ring positioned around a piston core.

Abstract: The construction described is a resistive sheet type of duct liner or duct silencer; i.e., a liner or silencer in which acoustical flow resistance is concentrated in a thin face sheet separating the flow passage and acoustical cavity rather than in an acoustically absorptive packing material filling the acoustical cavity. The invention disclosed is means for applying inexpensive perforated facings, similar to those in a conventional packed silencer, to provide resistive sheets which are effective in terms of noise dissipation and in terms of self-noise (noise generated by flow through the flow passages).

Abstract: Large mill reels of paper are protectively wrapped for shipment by a method which first caps the reel end-faces with a header disk having a diameter greater than the reel diameter. The flange of excess disk material is pleated and pressed into a band of adhesive applied about the reel circumference near the respective end-face. Subsequently, a second band of adhesive is applied to the two pleated and pressed flanges around the reel circumference and a circumferential surface wrap of width substantially equal to the axial length of the subject reel is applied thereabout.