Patent EP0645727A2 successfully refreshed from Google Patents.
US3568059A
Expired / Lapsed
US
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Electronic tachometer
Assignee: Information Storage Systems Inc
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Filing: 1969-01-21
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Granted: 1971-03-02
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Expires: 1989-01-21
Abstract
Abstract An electronic tachometer for providing a continuous indication of velocity of a motor-driven load including: a sensor operatively connected to the load for generating a periodic position signal; means for converting the position signal to an accurate indication of load velocity; a sample and hold circuit for periodically sampling the velocity measurement and retaining the level of the sample; an integrator for integrating the drive current applied to the motor; and a junction for recalibrating the integrated drive current with each retained sample to form a continuous velocity signal.
Inventors
- 👤 Frank J Sordello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:43
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1427; G01; G01P; G01P3/00; G01P3/42; G05D3/18; G05D3/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
A tachometer for providing a continuous indication of velocity of a motor driven load relative to a member, said tachometer comprising: first means operatively connected to said load for producing an intermittent signal directly proportional to the instantaneous velocity of said load to said member; second means operatively connected to said motor and responsive to changes in the velocity of said motor for producing a continuous signal proportional to the instantaneous velocity in the load relative to the member; and third means operatively connected to said first and second means for periodically resetting said continuous signal to a level proportional to said intermittent signal.
Claim 2
Dependent Claim
104 words
A tachometer for providing a continuous indication of velocity of a motor driven load relative to a member, said tachometer comprising: first means operatively connected to said load for producing an intermittent signal directly proportional to the instantaneous velocity of said load to said member; second means operatively connected to said motor and responsive to changes in the velocity of said motor for producing a continuous signal proportional to the instantaneous velocity in the load relative to the member; and third means operatively connected to said first and second means for periodically resetting said continuous signal to a level proportional to said intermittent signal.
Claim 3
Dependent Claim
64 words
A tachometer as defined in claim 1, wherein: the first means includes means for generating a periodic signal responsive to the relative position of the load and member; means for converting the periodic signal to an accurate indication of load velocity relative to the load; and means for periodically sampling the periodic velocity signal and retaining the sample for combination with the continuous signal.
Claim 4
Dependent Claim
29 words
A tachometer as defined in claim 1, wherein the second means includes means for integrating a function of the acceleration of the motor to provide the continuous velocity signal.
Claim 5
Dependent Claim
67 words
A tachometer as defined in claim 3, wherein: the first means includes a transducer associated with the load for generating a continuous alternating signal indicating the position of the load relative to the member; means for differentiating the position signal to produce a velocity signal; and means for sampling the differentiated signal at regular intervals and for retaining the sampled signal for combination with the continuous signal.
Claim 6
Dependent Claim
47 words
A tachometer as defined in claim 4, wherein: the means for differentiating includes an operational amplifier connected in a differentiator configuration; and the means for sampling includes a capacitor and means for charging the capacitor in one direction during acceleration and in the opposite direction during deceleration.
Claim 7
Dependent Claim
72 words
A tachometer as defined in claim 5, wherein: the means for charging the capacitor includes two complementary pairs of emitter-followers, one of which charges the capacitor in a negative direction, and a transistor switch connected between the emitter-followers of each pair, the switchs being controlled by a pulse train derived from the position signal to cascade the emitter-followers of each pair together during the sample portion of the sample and hold position.
Claim 8
Dependent Claim
56 words
A tachometer as defined in claim 3, wherein: the first means includes a transducer associated with the load for generating a digital signal indicating position of the load; circuitry for converting the digital position signal to a velocity signal; and sample and hold circuitry for sampling the velocity signal at regular intervals and retaining the sample.
Claim 9
Dependent Claim
37 words
A tachometer as defined in claim 7, wherein: the circuitry includes means for generating a current which is inversely proportional to velocity; and means for generating a voltage which is directly proportional to velocity from the current.
Claim 10
Dependent Claim
65 words
A tachometer as defined in claim 8, wherein: the means for generating a voltage includes a capacitor connected between two fixed voltage levels, the capacitor being connected to be discharged by the current; means for generating a gating signal proportional to the time of discharge of the capacitor; and ramp generating means controlled by the gating signal for producing a voltage directly proportional to velocity.
References Cited (Backward Citations)
US2934267A
Cited
US3359477A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |