Apparatus for sensing operating shock on a disk drive

• US 5,235,472 A
• Filed: 10/18/1991
• Issued: 08/10/1993
• Est. Priority Date: 10/18/1991
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Inventors: Smith, Robert F.
• Primary Examiner(s): Psitos, Aristotelis M.
• Assistant Examiner(s): HUBER, PAUL W
• Application Number:
  US07/779,214
• Time in Patent Office: 662 Days
• Field of Search: 310/312, 310/328, 310/338, 310/339, 310/340, 310/344, 310/348, 310/354, 310/360, 310/367, 310/368, 310/330, 310/333, 360/60, 360/66, 360/69, 73/517 R, 73/517 AV
• US Class Current: 360/60
• CPC Class Codes: G01P 15/0922 of the bending or flexing mode type
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G11B 19/04 Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: G11B 33/08 Insulation or absorption of undesired vibrations or sounds

Abstract

A shock load detection device mounted on a disk drive unit. The detection device is comprised of a piezoelectric polymer film encapsulated and electrically shielded by a metallic or metallic coated package. Electrical contacts are provided for on the piezoelectric polymer film and are connected to amplification and comparator circuitry which issues a write fault signal upon detection of external force in excess of a predetermined threshold. The shock sensor may be mounted on the computer disk drive of the unit in such a manner as to be at a 45° angle to each of the x, y and z axis of the orthogonal coordinate system so that linear and torsional forces may be monitored.

Claims

1. A shock and load detection device mounted on a disk drive unit comprising:

a relatively rectangular disc drive having at least three intersecting sides; and

a relatively planar shock sensor mounted on said disc drive;

the plane of said shock sensor intersecting each of the planes of said three sides at oblique angles.

2. The apparatus of claim 1, wherein the sensor comprises a piezoelectric polymer film.

3. The apparatus of claim 2, further comprised of:

amplifier means connected to the sensor means for producing a voltage signal proportional to the electrical charge received from the sensor means; and

comparator means connected to the amplifier means for evaluating the voltage signal to a predetermined threshold voltage, corresponding to a known acceleration level, and issuing a write-fault signal to suspend magnetic recording, when the voltage signal received by the comparator means exceeds the predetermined threshold voltage.

4. The apparatus of claim 2, further comprising a metallic case encapsulating the piezoelectric polymer film for electrical shielding purposes.

5. The apparatus of claim 2, further comprising a case having a metallized coating encapsulating the piezoelectric polymer film for electrical shielding purposes.

6. The apparatus of claim 2 mounted on the drive in such a manner so that the piezoelectric polymer film rests approximately 45°

to the x, y and z axis of the orthogonal coordinate system.

7. The apparatus of claim 2 wherein the piezoelectric polymer film is mounted within the metallic case at a 45°

angle longitudinally.