Abstract:
A method and apparatus are disclosed for using a numerically controlled turning machine to automatically cut a thread in response to programmed data defining certain thread cutting parameters. The programmed data defines an initial thread cutting pass and the final thread depth. The method and apparatus cause the cutting tool to make a number of iterative thread cutting passes relative to the rotating workpiece with successive passes being made at correspondingly smaller cutting depths. The threading cycle is terminated by two finish passes at a predetermined minimum depth of cut.
Abstract:
A conical blank is rotated and simultaneously advanced so that a milling cutter cuts a helical groove into the same. In order to obtain a constant helix angle and a constant peripheral speed of the successively cut blank portions of different diameter, the rotary speed of the blank is cyclically varied by a control device including a cam and a cam follower influencing a differential transmission which connects drive means with the rotary blank.
Abstract:
An optical film having structures that vary in height along their length where the variations have a nominal period of less than forty times the nominal height of the structures is taught. In some embodiments of the invention the variation is random.