US3825744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overspeed detector for vehicle control system
Assignee: SASIB SpA Bologna
•
Filing: 1973-03-26
•
Granted: 1974-07-23
•
Expires: 1993-03-26
Abstract
Abstract The Overspeed Detector for Vehicle Control Systems comprises a pair of high pass filters, having inputs governed by the actual vehicle speed signal, which deliver outputs only provided that the frequency of the inputs is above the frequency for the high pass filters, and the checking means includes an oscillator which generates a check signal with a frequency higher than the frequency of the high pass filters. The switching means alternately applies the check frequency to the inputs of the filters so that the filters alternately deliver output check frequency signals. Control means is governed jointly by outputs of the high pass filters and is operable to one state only when one of the filters at a time is delivering an output and operable to the other state when both filters deliver outputs contemporaneously.
Inventors
- 👤 H Sibley
- 👤 J Auer
- 👤 W Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:29
CPC Classifications
B; B61; B61L; B61L27/00; B61L27/20; B61L3/00; B61L3/02; B61L3/08; B61L3/12; B61L3/121; B61L23/00; B61L27/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
192 words
An overspeed detector for vehicle control system comprising sensing means for generating an alternating current actual speed signal for the vehicle and sensing means for delivering an alarm signal whenever the actual speed signal is indicative of a speed above a selected speed limit wherein the improvement comprises: a. a pair of high pass filters having inputs connected to the actual vehicle speed signal for delivering outputs of the respective filters only when the frequency of the inputs is above the cut off frequency for the high pass filters; b. checking means including an oscillator generating a check signal having a frequency higher than the cut off frequency of the high pass filters; and, c. switching means connected between said checking means and the input to each of said filters for alternately applying the check signal to the inputs of the filters, whereby the filters alternately deliver output check frequency signals, and d. control means governed jointly by the outputs of the high pass filters and operable to one state only when both filters at a time are delivering outputs alternately and operable to another state when both filters deliver outputs contemporaneously.
Claim 2
Dependent Claim
192 words
An overspeed detector for vehicle control system comprising sensing means for generating an alternating current actual speed signal for the vehicle and sensing means for delivering an alarm signal whenever the actual speed signal is indicative of a speed above a selected speed limit wherein the improvement comprises: a. a pair of high pass filters having inputs connected to the actual vehicle speed signal for delivering outputs of the respective filters only when the frequency of the inputs is above the cut off frequency for the high pass filters; b. checking means including an oscillator generating a check signal having a frequency higher than the cut off frequency of the high pass filters; and, c. switching means connected between said checking means and the input to each of said filters for alternately applying the check signal to the inputs of the filters, whereby the filters alternately deliver output check frequency signals, and d. control means governed jointly by the outputs of the high pass filters and operable to one state only when both filters at a time are delivering outputs alternately and operable to another state when both filters deliver outputs contemporaneously.
Claim 3
Dependent Claim
72 words
An overspeed detector according to claim 1 including said control means comprises: a. exclusive OR means having an input from each high pass filter for delivering a first output only when both filters alternately deliver output check frequency signals, and delivering another output when either filter delivers a steady-state signal, and b. underspeed relay means held energized by the first output by the exclusive OR means and de-energized by the other output.
Claim 4
Dependent Claim
50 words
An overspeed detector according to claim 1 wherein said switching means comprises: a clock for producing signals at a selected check rate, and contact means governed by the clock for alternately switching the oscillator output from one high pass filter input to the other in accordance with said check rate.
References Cited (Backward Citations)
US2719911A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |