Abstract: Methods of preventing ablation damage to a second wall or an underlying second article during the laser drilling of a first wall or an overlying first article are presented. The methods include a step of providing a dry, stable particulate material between the first and second walls or articles to shade the second wall or article from direct laser beam illumination during the laser machining of the first wall or article.

Abstract: A secondary pivot adapted to interrupt the periodic motion of a trapeze so as to cause the trapeze performer to experience rotational acceleration is disclosed. The term “secondary pivot” is defined to mean a selectively engageable pivot interposed at preselected intermediate positions along the respective lengths of the suspension lines of the trapeze between their points of suspension and the trapeze bar. A compound trapeze which includes a secondary pivot is also disclosed. Methods which include a step of restraining the periodic motion of a trapeze so as to cause the trapeze performer to experience rotational acceleration are also disclosed.

Abstract: An abrasive flow apparatus for polishing a workpiece wherein a horizontal machine tool is adapted such that a workpiece may be secured to first shaft rotatable about a first longitudinal axis. A conjugate form to the workpiece may be secured to a second shaft which is rotatable about a second longitudinal axis. The workpiece and conjugate form are secured to each shaft in a manner such that they are facing one another and slightly set apart to define a gap. A flowable abrasive media is introduced within this gap. The centerlines of the workpiece and the conjugate form are offset from one another such that rotation of the shafts in the same direction and at the same rotational speed produces relative motion between the workpiece and the conjugate form thereby polishing the workpiece. A slide may be used for axially positioning the first shaft and the second shaft a predetermined distance to define the size of the gap.

Abstract: A method and apparatus are disclosed for abrading the inner surface at the intersection region of a branch outlet with the wall of a body having a passageway. Using abrasive flow machining, it is possible to abrade the intersection region to provide a smooth transition between the wall and the branch outlet.

Abstract: A method and apparatus for comparing the flow rate through an orifice within a master part with the orifice within a workpiece by subjecting each orifice to an identical fluid at an identical temperature, under an identical pressure, and comparing the downstream pressures of the fluid exiting these orifices when the upstream pressure is constant or comparing the upstream pressure when the downstream pressure is constant. For purely measurement purposes, the fluid may be a non-abrasive media, however, in the event the workpiece orifice must be machined, it is possible to introduce a flowable abrasive media, and pass this media through the orifices until the desired pressure difference is achieved. With additional flow characteristics of the master part, it is also possible to calculate the flow rate through the workpiece orifice using only the pressure differential at the exits of the workpiece and the master part.