US3921047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overspeed protection system for centrifuge apparatus
Assignee: Beckman Coulter Inc
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Filing: 1973-04-02
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Granted: 1975-11-18
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Expires: 1993-04-02
Abstract
Abstract In an overspeed protection system for a centrifuge apparatus of the type which uses a coded reflective disk having alternate reflective and non-reflective sectors secured to a rotor to determine the maximum safe operating speed thereof, there is disclosed apparatus for detecting, upon start-up of the centrifuge, whether the disk is in place and operating properly. This is ascertained by determining whether the time durations of the signals from the rotor are greater or less than a predetermined minimum value. If they are greater than the minimum value, this is indicative of the fact that the coded disk is in proper position. If they are less than the minimum value, a power shutdown command is generated.
Inventors
- 👤 Alan W Carter
- 👤 Robert C Franklin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:59
CPC Classifications
F; F16; F16P; F16P7/00; B; B04; B04B; B04B13/00; B04B13/003; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/903; Y10S388/907; Y10S388/921; Y10S388/923; Y10S388/933
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
156 words
In an overspeed protection system for a centrifuge apparatus including a rotor driven by a drive motor; transducer means including a coded disk having a plurality of spaced sectors secured to said rotor and a detector assembly responsive to rotation of said disk for generating a signal for each waveform whose frequency is a function of the rotational speed of said rotor; and means coupled to the output of said transducer means and responsive the frequency of said periodic waveform for sensing an overspeed condition of said rotor, the improvement comprising: means coupled to the output of said transducer means during start up and inoperable after a given time interval therafter, said means responsive to the time duration of said signals from said detector assembly for generating a power shutdown command for said drive motor unless the time duration of at least one of said signals during said interval is greater than a predetermined minimum value.
Claim 2
Dependent Claim
156 words
In an overspeed protection system for a centrifuge apparatus including a rotor driven by a drive motor; transducer means including a coded disk having a plurality of spaced sectors secured to said rotor and a detector assembly responsive to rotation of said disk for generating a signal for each waveform whose frequency is a function of the rotational speed of said rotor; and means coupled to the output of said transducer means and responsive the frequency of said periodic waveform for sensing an overspeed condition of said rotor, the improvement comprising: means coupled to the output of said transducer means during start up and inoperable after a given time interval therafter, said means responsive to the time duration of said signals from said detector assembly for generating a power shutdown command for said drive motor unless the time duration of at least one of said signals during said interval is greater than a predetermined minimum value.
Claim 3
Dependent Claim
40 words
In an overspeed protection system according to claim 1, the improvement wherein said power shutdown command is generated unless the time durations of a plurality of said signals within the given time interval are greater than said predetermined minimum value.
Claim 4
Dependent Claim
22 words
In an overspeed protection system according to claim 2, the improvement wherein the number of said plurality of said signals is predetermined.
Claim 5
Dependent Claim
45 words
In an overspeed protection system according to claim 2, the improvement wherein said generating means includes means responsive to the occurrence of said plurality of said signals having time durations Greater than said predetermined minimum value for preventing further generation of said power shutdown command.
Claim 6
Dependent Claim
31 words
In an overspeed protection system according to claim 2, the improvement wherein said detector assembly generates a pulse for each received signal having an amplitude greater than a set threshold level.
Claim 7
Dependent Claim
20 words
In an overspeed protection system according to claim 2, the improvement wherein said predetermined minimum value is approximately 3 milliseconds.
Claim 8
Dependent Claim
130 words
In an overspeed protection system according to claim 1, the improvement wherein said power shutdown command generating means comprises: means coupled to the output of said transducer means and responsive to each of said signals therefrom for generating an inhibiting pulse having a time duration equal to said predetermined minimum value; gate means coupled to the output of said transducer means and to the output of said inhibiting pulse generating means for generating a gate pulse whenever the time duration of one of said signals from said transducer means exceeds the time duration of one of said inhibiting pulses; and confidence circuit means coupled to the output of said gate means for generating said power shutdown command unless a plurality of said pulses are received during a predetermined time interval.
Claim 9
Dependent Claim
41 words
In an overspeed protection system according to claim 7, the improvement wherein said confidence circuit means is responsive to the occurrence of said plurality of gating pulses during said predetermined time interval for preventing further generation of a power shutdown command.
Claim 10
Dependent Claim
52 words
In an overspeed protection system according to claim 8, the improvement wherein said power shutdown command generating means further comprises: means for applying the output of said confidence circuit means to said inhibiting pulse generating means for preventing further generation of inhibiting pulses, thereby preventing further generation of said power shutdown command.
Claim 11
Dependent Claim
96 words
In an overspeed protection system according to claim 1, wherein said coded disk has alternate reflective and non-reflective sectors, the total number of said sectors being related to the maximum speed of said rotor, the improvement wherein said transducer means includes: a light source positioned to direct light toward said reflective sectors of said disk; a phototransistor positioned to be responsive to light reflected from said disk; and a limiter amplifier responsive to said phototransistor and to a source of threshold voltage for generating a pulse whenever the signal from said phototransistor exceeds said threshold voltage.
Claim 12
Dependent Claim
133 words
In an overspeed protection system according to claim 10, the improvement wherein said power shutdown command generating means comprises: one-shot multivibrator means coupled to the output of said limiter amplifier means and responsive to each of said pulses therefrom for generating an inhibiting pulse having a time duration equal to said predetermined minimum value; gate means coupled to the output of said limiter amplifier means and to the output of said multivibrator means for generating a gating pulse whenever the time duration of one of said pulses from said limiter amplifier exceeds the time duration of one of said inhibiting pulses; and confidence circuit means coupled to the output of said gate means for generating said power shutdown command unless a plurality of said gating pulses are received during a predetermined time interval.
Claim 13
Dependent Claim
56 words
In an overspeed protection system according to claim 11, the improvement wherein said confidence circuit means comprises: charging circuit means responsive to said gating pulses for accumulating a charge; and gating circuit means responsive to said charging circuit means for generating said power shutdown command until the level of said charge reaches a predetermined threshold level.
Claim 14
Dependent Claim
56 words
In an overspeed protection system according to claim 12, the improvement wherein said power shutdown commanD generating means further comprises: means for applying the output of said gating circuit means as a reset signal to said multivibrator means for preventing further generation of inhibiting pulses when the level of said charge reaches said predetermined threshold level.
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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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |