Head suspension with resonance feedback transducer

#This application claims the benefit of U.S. Provisional application Ser. No. 60/018,167, filed May 23, 1996 abandoned.

#1. Field of the Invention

#The present invention relates generally to suspensions for supporting read/write heads over recording media. In particular, the present invention relates to a head suspension assembly with a strain transducer circuit thereon for detecting motion of the head suspension assembly out of a neutral position.

#FIG. 1 is an isometric view of a head suspension assembly including a strain transducer circuit on a load beam in accordance with the present invention.

#FIG. 2a is an isometric view of the suspension assembly shown in FIG. 1 undergoing twisting motion in the first torsion mode.

#FIG. 2b is an isometric view of the suspension assembly shown in FIG. 1 undergoing twisting motion in the second torsion mode.

#A head suspension assembly 8 which includes a strain transducer circuit 10 in accordance with the present invention is illustrated generally in FIG. 1. As shown, head suspension assembly 8 includes a load beam 12 having a base or mounting region 14 on a proximal end, a flexure 16 on a distal end, a relatively rigid region 17 adjacent to the flexure, and a radius or spring region 18 between the base 14 and rigid region 17. The flexure 16 supports a head slider (not shown) which is mounted on a head attachment region 13 and which "flies" on an air bearing created by a spinning magnetic disk (not shown). The head slider supports a read/write head (not shown) for transferring data to, and reading data from the spinning magnetic disk. A base plate 20 is welded to base 14 for mounting the load beam 12 to a disk drive actuator arm (not shown). Flexure 16 is a spring connection provided between a head slider and the distal end of the load beam 12 which permits the head slider to move in pitch and roll directions so that it can compensate for fluctuations of the spinning disk surface above which the slider flies. Many different types of flexures, also known as gimbals, are known to provide the spring connection allowing for pitch and roll movement of the head slider and can be used with the present invention. First and second edge rails 23 and 24 are formed in transversely opposite sides of the rigid region 17 of load beam 12. Tab 26 which extends from base 14 is used to position and support read/write head lead wires (not shown), transducer circuit lead wires 28a and 28b, and electrical contacts 30.

#The strain transducer circuit 10 is located in the transverse center of load beam 12 and functions as a strain gauge. Strain gauges are well known in the art and any suitable strain gauge is contemplated to be used with the present invention. In the embodiment of FIG. 1, individual transducer circuit lead 32 of transducer circuit 10 is formed from a single electrical lead which extends longitudinally back and forth in parallel sections connected at ends of the sections. Other orientations and configurations of circuit lead 32 are also within the ambit of the present invention. For example the electrical lead can be configured in a circular spiral or other non-parallel configurations. FIG. 5 is a sectional view of load beam 12 taken along line 5--5 and showing transducer circuit lead 32. Lead wires 28a and 28b are connected to opposite ends of circuit lead 32 to form a continuous closed circuit between lead wires 28a and 28b. FIG. 6 is a sectional view of load beam 12 taken along line 6--6 and showing lead wires 28a and 28b. Lead wires 28a and 28b are connected to contacts 30 on tab 26.

#Transducer circuit lead 32 is fabricated of a material in which the electrical resistance varies with strain on the material. In the embodiment of FIG. 1, circuit lead 32 is formed of Constantan, a commercially available nickel-copper alloy. Transducer circuit lead 32 can also be formed of any other material in which electrical resistance varies as the strain on the material varies.