Patent US4177459A successfully refreshed from Google Patents.
US4177459A
Expired / Lapsed
US
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Fail-safe acknowledging circuit
Assignee: Trane US Inc
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Filing: 1977-05-24
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Granted: 1979-12-04
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Expires: 1997-05-24
Abstract
Abstract A fail-safe solid-state acknowledging circuit for a cab signaling system requiring an acknowledgment after the reception of a more restrictive speed command signal employing a plurality of transistor latching circuits having a predetermined order of more restrictive significance. Each of the transistor latching circuits is coupled to one input of a separate two input OR gate while a separate a.c. transistor amplifier is coupled to the other input of each of the two input OR gates. The outputs of the OR gates along with an acknowledging switch controlled voltage are coupled to the inputs of a multiple input AND gate for normally holding the AND gate in a signal passing condition and for causing the AND gate to assume a signal blocking condition when a more restrictive speed command signal is received onboard a vehicle.
Inventors
- 👤 John O. G. Darrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:23
CPC Classifications
B; B60; B60L; B60L3/00; B60L2200/00; B60L2200/26
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A fail-safe electronic circuit arrangement which requires an acknowledgment after the reception of a more restrictive input signal in order to reestablish an output signal comprising, a plurality of latching means connectable to a separate one of a plurality of input signals having a predetermined order of more restrictive significance, one of a plurality of gating means cooperatively associated with a separate one of said plurality of latching means, and a multiple input gating means coupled to said plurality of latching and gating means for producing an output signal and conditioned upon the reception of a more restrictive input signal for causing the removal of the output signal.
Claim 2
Dependent Claim
108 words
A fail-safe electronic circuit arrangement which requires an acknowledgment after the reception of a more restrictive input signal in order to reestablish an output signal comprising, a plurality of latching means connectable to a separate one of a plurality of input signals having a predetermined order of more restrictive significance, one of a plurality of gating means cooperatively associated with a separate one of said plurality of latching means, and a multiple input gating means coupled to said plurality of latching and gating means for producing an output signal and conditioned upon the reception of a more restrictive input signal for causing the removal of the output signal.
Claim 3
Dependent Claim
24 words
A fail-safe circuit arrangement as defined in claim 1, wherein each of said plurality of latching means includes a pair of transistor amplifying stages.
Claim 4
Dependent Claim
23 words
A fail-safe circuit arrangement as defined in claim 1, wherein each of said plurality of gating means includes a two input OR gate.
Claim 5
Dependent Claim
21 words
A fail-safe circuit arrangement as defined in claim 1, wherein said multiple input gating means is a four input AND gate.
Claim 6
Dependent Claim
80 words
A fail-safe circuit arrangement as defined in claim 1, wherein each of said plurality of latching means including a first and a second amplifier, said first amplifier having its input coupled to a source of periodic input signals being set by a negative d.c. operating voltage for producing amplified a.c. signals, means coupling said amplified a.c. signals to the input of said second amplifier, said second amplifier being conditioned by a negative HOLD supply voltage for producing a.c. output signals.
Claim 7
Dependent Claim
39 words
A fail-safe circuit arrangement as defined in claim 1, wherein selected ones of said plurality of said gating means includes a pair of voltage doubling rectifier networks for producing a d.c. output voltage for said multiple input gating means.
Claim 8
Dependent Claim
38 words
A fail-safe circuit arrangement as defined in claim 1, wherein at least one of said plurality of said gating means includes a pair of clamping circuits for producing an a.c. output signal for said multiple input gating means.
Claim 9
Dependent Claim
25 words
A fail-safe circuit arrangement as defined in claim 1, wherein said multiple input gating means includes three emitter-follower stages and a complementary power output stage.
Claim 10
Dependent Claim
47 words
A fail-safe circuit arrangement as defined in claim 1, wherein said latching means is set by the actuation of a switch which supplies a charging voltage to the capacitor for providing operating potential to a transistor amplifier for providing a.c. signals to a voltage doubling rectifier network.
Claim 11
Dependent Claim
58 words
A fail-safe circuit arrangement as defined in claim 1, wherein said plurality of gating means includes a two input OR gate in which either the associated latching means supplies a.c. signals to one of the two inputs or a transistor amplifier supplies a.c. signals to the other of the two inputs when a less restrictive signal is received.
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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) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |