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US4306180A Expired / Lapsed US ⏱️ 0.0 years remaining

Directional control system

Assignee: Yale Materials Handling Corp
•
Filing: 1980-02-29
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Granted: 1981-12-15
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Expires: 2000-02-29
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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)

US2098069A Cited
US2264993A Cited
US2424859A Cited
US2543450A Cited
US2990505A Cited
US3305718A Cited

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

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