US4306180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directional control system
Assignee: Yale Materials Handling Corp
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Filing: 1980-02-29
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Granted: 1981-12-15
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Expires: 2000-02-29
Abstract
Abstract A circuit for controlling the drive direction of an electrically-driven vehicle, the circuit having a plurality of spring return input switches (20) each actuation of which changes the direction of the vehicle, via a flip-flop circuit (21), an amplifier (22), and a relay (13); the direction contactor coils (10, 11) of the vehicle being connected in alternative circuits through the contacts of the relay (13).
Inventors
- 👤 John B. Moore
- 👤 Derek W. Rice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:43
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/03
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
In a circuit for controlling the drive direction of an electrically driven vehicle, the circuit comprising forward and reverse contactor coils controlling the drive direction, contact means movable between a first position energizing said forward contactor coil and a second position energizing said reverse contactor coil, a relay coil having a movable core member connected to said contact means and operable to move said contact means to one of said first or second positions when said relay coil is energized and to the other of said first or second positions when said relay coil is deenergized, and an input switch controlling energization of the relay coil; the improvement comprising a flip-flop circuit controlled by said input switch and having an input connected to a voltage source and an output connected to said relay coil, said flip-flop circuit having a first output level sufficient to energize said relay coil and a second output level insufficient to energize said relay coil, said first and second output levels of said flip-flop circuit being selected alternately each time said input switch is closed.
Claim 2
Dependent Claim
179 words
In a circuit for controlling the drive direction of an electrically driven vehicle, the circuit comprising forward and reverse contactor coils controlling the drive direction, contact means movable between a first position energizing said forward contactor coil and a second position energizing said reverse contactor coil, a relay coil having a movable core member connected to said contact means and operable to move said contact means to one of said first or second positions when said relay coil is energized and to the other of said first or second positions when said relay coil is deenergized, and an input switch controlling energization of the relay coil; the improvement comprising a flip-flop circuit controlled by said input switch and having an input connected to a voltage source and an output connected to said relay coil, said flip-flop circuit having a first output level sufficient to energize said relay coil and a second output level insufficient to energize said relay coil, said first and second output levels of said flip-flop circuit being selected alternately each time said input switch is closed.
Claim 3
Dependent Claim
29 words
Apparatus as claimed in claim 1, including a pair of direction indicator lamps responsive to the energization and deenergization of said relay coil to indicate the drive direction selected.
Claim 4
Dependent Claim
16 words
Apparatus as claimed in claim 1, in which said input switch is a spring return switch.
Claim 5
Dependent Claim
30 words
Apparatus as claimed in claim 3, in which said vehicle has at least one hydraulic function operating lever, said input switch being mounted at the end of said operating lever.
Claim 6
Dependent Claim
19 words
Apparatus as claimed in claim 4, in which said input switch is recessed in the end of said lever.
References Cited (Backward Citations)
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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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |