US3852616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency selection by period timing
Assignee: Bendix Corp
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Filing: 1973-02-21
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Granted: 1974-12-03
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Expires: 1993-02-21
Abstract
Abstract A period timer for use in an adaptive braking system determines when wheel speed falls below a reference speed and when wheel speed subsequently exceeds a second, higher, reference speed. A capacitor is charged to a voltage inversely proportional to wheel speed. If the capacitor voltage exceeds a reference voltage proportional to the reference speed a one-shot generates an output which is fed back to lower the reference voltage.
Inventors
- 👤 G Krawczak
- 👤 R Carp
- 👤 H Weissler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:00
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
178 words
A period timer for use in an adaptive braking system for generating an output signal when a speed represented by a speed signal falls below a first reference speed, said output signal being extinguished when the speed subsequently exceeds a second higher reference speed comprising: means for generating an electrical pulse train having a pulse repetition frequency proportional to the speed signal; means for generating a voltage ramp from a first voltage level toward a second voltage level; means responsive to a predetermined, cyclically recurring point on said pulse train for returning said voltage ramp to said first voltage level; means for generating a reference voltage level proportional to said first reference speed; a retriggerable one-shot; a comparator for triggering said one-shot to generate said output signal when the instantaneous value of said voltage ramp attains said reference voltage level, said output signal having at least a predetermined period; and, feedback means responsive to said output signal for altering said reference voltage level to be proportional to said second reference speed during the period of said output signal.
Claim 2
Dependent Claim
178 words
A period timer for use in an adaptive braking system for generating an output signal when a speed represented by a speed signal falls below a first reference speed, said output signal being extinguished when the speed subsequently exceeds a second higher reference speed comprising: means for generating an electrical pulse train having a pulse repetition frequency proportional to the speed signal; means for generating a voltage ramp from a first voltage level toward a second voltage level; means responsive to a predetermined, cyclically recurring point on said pulse train for returning said voltage ramp to said first voltage level; means for generating a reference voltage level proportional to said first reference speed; a retriggerable one-shot; a comparator for triggering said one-shot to generate said output signal when the instantaneous value of said voltage ramp attains said reference voltage level, said output signal having at least a predetermined period; and, feedback means responsive to said output signal for altering said reference voltage level to be proportional to said second reference speed during the period of said output signal.
Claim 3
Dependent Claim
178 words
A period timer for use in an adaptive braking system for generating an output signal when a speed represented by a speed signal falls below a first reference speed, said output signal being extinguished when the speed subsequently exceeds a second higher reference speed comprising: means for generating an electrical pulse train having a pulse repetition frequency proportional to the speed signal; means for generating a voltage ramp from a first voltage level toward a second voltage level; means responsive to a predetermined, cyclically recurring point on said pulse train for returning said voltage ramp to said first voltage level; means for generating a reference voltage level proportional to said first reference speed; a retriggerable one-shot; a comparator for triggering said one-shot to generate said output signal when the instantaneous value of said voltage ramp attains said reference voltage level, said output signal having at least a predetermined period; and, feedback means responsive to said output signal for altering said reference voltage level to be proportional to said second reference speed during the period of said output signal.
Claim 4
Dependent Claim
178 words
A period timer for use in an adaptive braking system for generating an output signal when a speed represented by a speed signal falls below a first reference speed, said output signal being extinguished when the speed subsequently exceeds a second higher reference speed comprising: means for generating an electrical pulse train having a pulse repetition frequency proportional to the speed signal; means for generating a voltage ramp from a first voltage level toward a second voltage level; means responsive to a predetermined, cyclically recurring point on said pulse train for returning said voltage ramp to said first voltage level; means for generating a reference voltage level proportional to said first reference speed; a retriggerable one-shot; a comparator for triggering said one-shot to generate said output signal when the instantaneous value of said voltage ramp attains said reference voltage level, said output signal having at least a predetermined period; and, feedback means responsive to said output signal for altering said reference voltage level to be proportional to said second reference speed during the period of said output signal.
Claim 5
Dependent Claim
125 words
The period timer of claim 1 and with additionally: a second period timer essentially identical to the first mentioned period timer for generating a second output signal when a speed represented by a second speed signal falls below a third reference speed represented by a third reference voltage level, and including further feedback means for altering said third reference voltage level to a fourth reference voltage level representing a fourth reference speed during the period of said second output signal, said second output signal being extinguished when the speed represented by the second speed signal subsequently exceeds the fourth reference speed; and, means for generating a brake control signal while one of the output signals is generated in the absence of the other output signal.
Claim 6
Dependent Claim
57 words
The period timer of claim 1 wherein said means for generating a reference voltage level comprises a d-c power source and a voltage divider connected thereacross, said reference voltage level being obtained from a point interior thereof, and wherein said feedback means comprises resistance means switchably connected into said voltage divider in response to said output signal.
Claim 7
Dependent Claim
73 words
The period timer of claim 4 with additionally: a second period timer for generating a second output signal when the speed of a second sensed wheel falls below said first speed, said second output signal being extinguished when the speed of said second wheel subsequently exceeds said second speed; and, means for generating a brake control signal when one of the output signals is generated in the absence of the other output signal.
Claim 8
Dependent Claim
72 words
The period timer of claim 4 wherein said comparator includes an output terminal and wherein said retriggerable one-shot comprises: an amplifier having an input terminal connected to said comparator output terminal and an amplifier output terminal, said output signal being generated at said amplifier output terminal; a second capacitor connected between said amplifier input terminal and a return terminal of said d-c power source; and, resistor means connected across said second capacitor.
Claim 9
Dependent Claim
59 words
The period timer of claim 6 wherein said comparator supplies current to said second capacitor when triggering and retriggering but where said comparator does not sink current into its output terminal, and wherein said amplifier is characterized by a high input impedance input terminal whereby the only effective discharge path of said second capacitor is through said resistor means.
Claim 10
Dependent Claim
50 words
The period timer of claim 7 wherein said amplifier is an inverting threshold amplifier and wherein said voltage divider includes an interior point thereof, said reference voltage level being generated at said interior point, and wherein said feedback means is connected between said interior point and said amplifier output terminal.
Claim 11
Dependent Claim
51 words
The period timer of claim 8 wherein said means for temporarily shunting said capacitor comprises: a transistor having a collector-emitter circuit connected across said capacitor and a base electrode; and, a differentiator having an input terminal connected to receive said electrical wave and an output terminal connected to said base electrode.
Claim 12
Dependent Claim
75 words
The period timer of claim 4 and with additionally: a second period timer for generating a second output signal when the speed of a second sensed wheel falls below said first speed, said second output signal being extinguished when the speed of said second sensed wheel subsequently exceeds said second speed; and, means for generating a brake control signal when one of the output signals is generated in the absence of the other output signal.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |