US3617835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Operating means for reciprocating mechanism
Assignee: ThyssenKrupp Budd Co
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Filing: 1969-09-29
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Granted: 1971-11-02
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Expires: 1989-09-29
Abstract
Abstract A bidirectional motor includes armature and field windings. A switching circuit connects power to drive the motor in a first direction. A detector is responsive to a decrease in the current flow in the armature winding to stop the motor and then switch the switching circuit to apply the power to drive the motor in a second direction.
Inventors
- 👤 Stephen T Dreher
- 👤 John W Marchetti
- 👤 Gary H Stock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:45
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/03
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
250 words
In combination with a bidirectional motor having armature and field windings, a source of power for driving said motor, a switching circuit for applying current from said source of power to said armature and field windings to drive said motor in a first or second direction, said switching circuit including first and second switches, said second switch having first and second operating conditions, a first relay operative to close said first switch to connect said source of power through said second switch to drive said motor in a first direction when said second switch is in a first operating condition, a zener diode responsive to a back e.m.f. generated in said armature winding to control the operation of said first relay to disconnect or connect said source of power to stop or start said motor, said zener diode being conductive to actuate said first relay when said motor is moving at a predetermined speed to generate a counter e.m.f. of a predetermined amplitude, said zener diode becoming nonconductive to maintain said first relay unactuated and cause said motor to stop when said motor starts to move below said predetermined speed to generate a counter e.m.f. below said predetermined amplitude, and a second relay to switch said second switch from said first to said second operating condition and to reactuate said first relay to switch the direction of current from said source of power to said field winding to drive said motor in a second direction after a predetermined time period.
Claim 2
Dependent Claim
250 words
In combination with a bidirectional motor having armature and field windings, a source of power for driving said motor, a switching circuit for applying current from said source of power to said armature and field windings to drive said motor in a first or second direction, said switching circuit including first and second switches, said second switch having first and second operating conditions, a first relay operative to close said first switch to connect said source of power through said second switch to drive said motor in a first direction when said second switch is in a first operating condition, a zener diode responsive to a back e.m.f. generated in said armature winding to control the operation of said first relay to disconnect or connect said source of power to stop or start said motor, said zener diode being conductive to actuate said first relay when said motor is moving at a predetermined speed to generate a counter e.m.f. of a predetermined amplitude, said zener diode becoming nonconductive to maintain said first relay unactuated and cause said motor to stop when said motor starts to move below said predetermined speed to generate a counter e.m.f. below said predetermined amplitude, and a second relay to switch said second switch from said first to said second operating condition and to reactuate said first relay to switch the direction of current from said source of power to said field winding to drive said motor in a second direction after a predetermined time period.
Claim 3
Dependent Claim
35 words
The invention as set forth in claim 1 wherein a second switching circuit is provided to initiate the current flow from said source of power through said armature and field windings to start said motor.
Claim 4
Dependent Claim
96 words
The invention as set forth in claim 2 wherein said second switching circuit comprises a third relay for actuating a switch to connect said source of power to initiate said current flow, means for actuating said third relay, said last-named means including a charging and discharging circuit, said last-mentioned circuit becoming charged when said second relay is operative to connect said source of power thereto and becoming discharged when said second relay is inoperative to disconnect said source of power therefrom said third relay becoming operative during the time that said circuit is charging or discharging.
Claim 5
Dependent Claim
26 words
The invention as set forth in claim 3 wherein a timer circuit is provided to control the time duration of the operation of said second relay.
Claim 6
Dependent Claim
15 words
The invention as set forth in claim 4 wherein said motor drives a reciprocating mechanism.
Claim 7
Dependent Claim
16 words
The invention as set forth in claim 5 wherein said reciprocating mechanism includes a train door.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |