Abstract: A calibration disk for calibrating the fly height of a head, includes spaced circumferencial bands on the disk extending in a concentric fashion from adjacent an outer diameter of the disk to near an inner diameter of the disk. Each of the bands include radial and circumferencial spaced asperity emulating bumps having a population sufficient to produce a constant and continuous output signal from a glide head when the glide head flies lower than a maximum height of the bumps. The height of the bumps within individual bands are substantially uniform, and the average heights of the bumps in each band differ from each other. The configuration of the bumps on the calibration disk advantageously avoids errors caused by disk waviness, runout, and contamination. Further, using the differing heights of the bumps on the calibration disk, a glide head can be calibrated on the glide tester without using an independent fly height measurements for the glide head.

Abstract: A simplified heavy-duty press having a bed and a support head mounted from the press bed for limited vertical movement under predetermined spring preload. The entire drive (less motor) and rams are carried from the press head and these components are movable away from the bed when the tools between the ram and bed encounter an obstruction beyond the preload. The preload limits maximum operative force that will be transmitted in the mechanisms where precise control of the components/dimensions may be difficult to maintain because of manufacturing limitations or because of thermal expansion.

Abstract: A pre-loading and energy absorbing mechanism in a press having a ram and a primary overload release comprising a preloaded spring assembly interposed between connecting rod pin and the ram and the connecting means to the tooling to take up excessive loads which develop due to thermal expansion or improper positioning of the tooling or kiss-block or an article to be formed or because of malfunction in the tooling, and a secondary higher overload release comprising a pre-loaded spring assembly interposed between the ram supporting head or the base of a press and the connecting structure therebetween, the head/base being movable away from and back to a fixed position in a connecting structure.