Abstract: An improved head loader is disclosed for use in assembling hard disk drives to permit the placement of magnetic heads over desired tracks of the magnetic disks. The loader includes a main frame, through which is disposed a shaft. The shaft passes through the frame and is secured to a positioning piece which includes an upwardly extending guide pin, and a downwardly extending positioning pin. A guide piece having a plurality of guides is rigidly attached to the frame. In operation, spreading blades pass through the guides and separate the magnetic heads on an actuator arm to permit the movement of the actuator arm to a position over desired areas of the magnetic disks, without the magnetic heads contacting the disks and causing damage.

Abstract: A Winchester disc spindle construction provides a spindle motor coil wound around laminated formed annular plates and having lead wires extending through a central stationary shaft. Surrounding a spindle coil is a cylinder having a pocket for arcuate permanent magnets. The discs are fixed to and rotated by the cylinder. Relatively large bearings support the cylinder concentric with the shaft and give increased strength to the structure, permitting more discs to be supported in equivalent space, as compared with prior structures. The arms carrying the read-write heads are mounted on a stack of spaced-apart arms pivotted at a distance from the discs so that the heads move along a shallow arc to reduce skewing of the heads relative to the recording tracks of the discs.

Abstract: A channel filter employing time domain targeting techniques to eliminate inter symbol interference in the reading of information from magnetic media. A pulse detector outputs a signal characteristic of polarity reversals on the surface of magnetic storage media. This output signal is coupled to a tapped delay line network and a moderate order L-C network. The tapped delay line provides an output signal to the L-C network, which flattens out pre-cursive and post-cursive undershoots. As a result, a moderate order L-C network is sufficient to approximate the desired target response so that maximum information density can be achieved. The tapped delay line provides an output signal that consists of a superposition (sum) of the input signal delayed and weighted. This forms a transversal filter. As with any linear filter, reciprocity applies. Consequently, the output of the tapped delay line is taken from the input with AC coupling directly to ground.