Abstract: A process and apparatus for dissipating static electrical charge that may build up on the small plastic parts, the tumbling medium or the tumbling chamber itself during an abrasive tumbling process and cause the parts to be repelled out of the abrasive medium. A flow of ionized gas is distributed about the tumbling chamber, discharges the parts and provides a mechanical action to return the parts to the abrasive medium. This flow of ionized gas dissipates the static charge.

Abstract: A method and apparatus for forming a round end on a small plastic filament which includes a die having a channel extending into one side with a hemispherical interior end and a bore extending into the other side and coaxially aligned with the channel and having a conic interior end. The tip of the conic section communicates with the hemispherical section. A relief recess is spaced from the periphery of the hemispherical section by a land portion. The peripheral edge of the land portion, which also forms the edge of the channel, may be formed into a knife edge. In the die the filament is cold-formed to provide a hemispherical section spaced apart from the distal end of the filament. Material displaced during the cold-forming process is deposited in a relief section extending peripherally about the channel.

Abstract: A method and apparatus for operating a center pivot irrigation system including a plurality of span units, each having a drive carriage having a hydraulically driven motor means for operating associated carriage wheels in response to hydraulic fluid supplied thereto under pressure through hydraulic fluid lines from a source thereof, is operated by supplying hydraulic fluid at a selectable value of constant volume fluid flow to the system to drive the system at a selectable average speed about its center pivot, the flow rate of fluid to individual motor means of individual span units which are ahead or behind of a predetermined relative alignment with the other span units being varied in response to changes in angularity sensed between adjacent span units in both forward and backward directions relative to the direction of travel of the system about its center pivot while the constant volume fluid flow through the system is being maintained at a selectable constant flow rate.