Patent US3725668A successfully refreshed from Google Patents.
US3725668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotational speed sensor
Assignee: Borg Warner Corp
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Filing: 1971-06-28
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Granted: 1973-04-03
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Expires: 1991-06-28
Abstract
Abstract A rotational speed sensor for producing a d.c. level output signal proportional to shaft speed is disclosed having a light responsive unit (phototransistor) which is masked from a light source by a pair of slotted discs. One disc defines windows and revolves directly with the shaft and the other defines shades for the windows and is mounted to be rotated by a centrifugal force mechanism mounted to revolve directly with the shaft. By means of a cam surface and groove, the second disc is caused to move relative to the first disc to unshade the window progressively as rotational speed increases. The light responsive unit is preferably of the self-integrating (long time constant) type to time average its output and produce the d.c. signal directly.
Inventors
- 👤 K Padgitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:22
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/02; G01P3/16; G01P3/22; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/486
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
206 words
A rotational speed sensor for producing a signal representative of the rotational speed of a shaft mounted for rotation comprising: a first mask member coupled to rotate with the shaft at a rotational speed which is a function of the rotational speed of the shaft said first member defining at least one window; a second mask member coupled to rotate with the shaft at a rotational speed which is a function of the rotational speed of the shaft, said second member defining means for shading at least said one window of said first member; said first member and said second member being mounted to allow movement relative to each other; a light source; a light responsive unit for producing an electrical signal in response to the quantity of light incident thereon; said source and said unit being operatively associated with said masks to produce an electrical signal from said unit that varies as a function of the relative positions of said masks; and means for moving said members relative to each other in response to the rotation of said shaft, said means for moving including a mass mounted for rotation with the shaft and a spring for mechanically biasing said mass toward its center of rotation.
Claim 2
Dependent Claim
206 words
A rotational speed sensor for producing a signal representative of the rotational speed of a shaft mounted for rotation comprising: a first mask member coupled to rotate with the shaft at a rotational speed which is a function of the rotational speed of the shaft said first member defining at least one window; a second mask member coupled to rotate with the shaft at a rotational speed which is a function of the rotational speed of the shaft, said second member defining means for shading at least said one window of said first member; said first member and said second member being mounted to allow movement relative to each other; a light source; a light responsive unit for producing an electrical signal in response to the quantity of light incident thereon; said source and said unit being operatively associated with said masks to produce an electrical signal from said unit that varies as a function of the relative positions of said masks; and means for moving said members relative to each other in response to the rotation of said shaft, said means for moving including a mass mounted for rotation with the shaft and a spring for mechanically biasing said mass toward its center of rotation.
Claim 3
Dependent Claim
79 words
The invention as defined in claim 1, wherein: said first member is affixed to the shaft; said second member is mounted on the shaft for movement relative thereto; said means for moving moves said second member relative to the shaft and the first member in response to the outward movement of said mass, and includes a cam member as part of the spring and a cam slot defined in said second member in which said cam member may move.
Claim 4
Dependent Claim
157 words
A speed sensor for sensing the speed of a rotatable shaft comprising: a plurality of members coupled to the shaft so as to rotate with the shaft at a speed which is a function of the shaft rotational speed, said members being mounted so as to allow their angular position relative to each other to change; signal producing means coupled to said members for producing an output signal which signal varies as a funCtion of the relative angular position of said members; and centrifugal force means including a mass mounted to orbit about an axis at a speed which is a function of the rotation speed of the shaft and to be radially displaced from the axis as a function of said orbit speed, said centrifugal force means being coupled to said members to change the relative angular position of said members in response to the radial displacement of said orbiting mass of said centrifugal force means.
Claim 5
Dependent Claim
157 words
A speed sensor for sensing the speed of a rotatable shaft comprising: a plurality of members coupled to the shaft so as to rotate with the shaft at a speed which is a function of the shaft rotational speed, said members being mounted so as to allow their angular position relative to each other to change; signal producing means coupled to said members for producing an output signal which signal varies as a funCtion of the relative angular position of said members; and centrifugal force means including a mass mounted to orbit about an axis at a speed which is a function of the rotation speed of the shaft and to be radially displaced from the axis as a function of said orbit speed, said centrifugal force means being coupled to said members to change the relative angular position of said members in response to the radial displacement of said orbiting mass of said centrifugal force means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |