US5389850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotational shock sensor
Assignee: Maxtor Corp
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Filing: 1994-02-04
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Granted: 1995-02-14
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Expires: 2014-02-04
Abstract
Abstract A sensor for sensing rotational displacements of a body comprises an elongated beam of a material providing a piezoelectric effect. The elongated beam has a first and second ends and a central portion, with the ends of the beam being attached to an interior surface of a case. The case, in turn, is attached to the body. When the body is subject to rotational accelerations, the beam is stressed, and a piezoelectric voltage is generated across the length of the beam.
Inventors
- 👤 Richard K. Wilmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:02
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/0888
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
87 words
A sensor for sensing rotational displacement of a body comprising: an elongated beam of a material providing a piezoelectric effect, said beam having a pair of ends and a central portion; a case attached to said body, said case having an interior surface, said beam being fixedly attached to said interior surface at said ends; a flywheel attached to said beam, rotational displacement of said body causing said flywheel to stress said crystal so as to generate a voltage across said beam due to said piezoelectric effect.
Claim 2
Dependent Claim
87 words
A sensor for sensing rotational displacement of a body comprising: an elongated beam of a material providing a piezoelectric effect, said beam having a pair of ends and a central portion; a case attached to said body, said case having an interior surface, said beam being fixedly attached to said interior surface at said ends; a flywheel attached to said beam, rotational displacement of said body causing said flywheel to stress said crystal so as to generate a voltage across said beam due to said piezoelectric effect.
Claim 3
Dependent Claim
16 words
The sensor of claim 1 further comprising means coupled to said beam for detecting said voltage.
Claim 4
Dependent Claim
16 words
The sensor of claim 2 wherein said detecting means further comprises means for amplifying said voltage.
Claim 5
Dependent Claim
25 words
The sensor of claim 1 wherein said sensor generates said voltage in response to rotational accelerations, but is insensitive to linear accelerations of said body.
Claim 6
Dependent Claim
18 words
The sensor of claim 4 wherein said flywheel is fixedly attached to said beam at said central portion.
Claim 7
Dependent Claim
36 words
The sensor of claim 5 wherein said beam further comprises a pair of electrodes attached at each end of said beam, said electrode providing electrical contact to said beam, with said voltage appearing across said electrodes.
Claim 8
Dependent Claim
12 words
The sensor of claim 1 wherein said flywheel is circular in shape.
Claim 9
Dependent Claim
12 words
The sensor of claim 6 wherein said material comprises a piezoelectric ceramic.
Claim 10
Dependent Claim
10 words
The sensor of claim 8 wherein said case comprises plastic.
Claim 11
Dependent Claim
35 words
The sensor of claims 1,2, 3, 4, 5, 6, 7, 8 or 9 wherein said flywheel is enclosed within said case, a clearance space existing between said flywheel and said interior surface of said case.
Claim 12
Dependent Claim
145 words
The rotational shock sensor for sensing rotational accelerations in a disk drive unit employing a rotating disk for data storage, said sensor comprising: a case attached to said disk drive unit, said case forming an enclosure; an elongated beam comprising a piezoelectric material, said beam having first and second ends, and a center region, disposed along a primary axis, said first and second ends being bonded to said case within said enclosure, said beam having at least one electrode at each of said first and second ends; a flywheel attached to said center region of said beam, said flywheel and said beam being housed within said enclosure with a space being formed between said flywheel and said case, said flywheel imparting a moment to said beam in response to a rotational acceleration of said disk drive unit, said moment generating a voltage across said electrodes.
Claim 13
Dependent Claim
145 words
The rotational shock sensor for sensing rotational accelerations in a disk drive unit employing a rotating disk for data storage, said sensor comprising: a case attached to said disk drive unit, said case forming an enclosure; an elongated beam comprising a piezoelectric material, said beam having first and second ends, and a center region, disposed along a primary axis, said first and second ends being bonded to said case within said enclosure, said beam having at least one electrode at each of said first and second ends; a flywheel attached to said center region of said beam, said flywheel and said beam being housed within said enclosure with a space being formed between said flywheel and said case, said flywheel imparting a moment to said beam in response to a rotational acceleration of said disk drive unit, said moment generating a voltage across said electrodes.
Claim 14
Dependent Claim
16 words
The sensor of claim 11 further comprising means attached to said electrodes for detecting said voltage.
Claim 15
Dependent Claim
46 words
The sensor of claim 12 wherein said disk drive unit includes a circuit for writing data to said disk, said circuit being disposed on a printed circuit board, and wherein said detecting means further comprises means for disabling said writing means in response to said voltage.
Claim 16
Dependent Claim
57 words
The sensor of claim 11 wherein said beam includes first and second polling fields formed along said primary axis, said first polling field being formed between said first end and said center region, with said second polling field being formed between second end and said center region in a direction opposite to that said first polling field.
Claim 17
Dependent Claim
27 words
The sensor of claim 14 wherein said sensor generates said voltage in response to rotational accelerations, but is insensitive to linear accelerations of said disk drive unit.
Claim 18
Dependent Claim
12 words
The sensor of claim 15 wherein said flywheel is circular in shape.
Claim 19
Dependent Claim
12 words
The sensor of claim 16 wherein said material comprises a piezoelectric ceramic.
Claim 20
Dependent Claim
10 words
The sensor of claim 17 wherein said case comprises plastic.
Claim 21
Dependent Claim
38 words
The sensor of claims 11, 12, 13, 14, 15, 16, 17 or 18 wherein said disk rotates in a first general plane and said beam lies within a second general plane substantially parallel to said first general plane.
Claim 22
Dependent Claim
15 words
The sensor of claim 19 wherein said case comprises an outer housing and a cover.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-13 | 1998-08-15 | 1999-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-13 | 2002-08-15 | 2003-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-13 | 2006-08-15 | 2007-02-14 | $7700.00 | Window Closed / Lapsed |