US4243920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control device for monitoring machines driving revolving devices and method for operating the device
Assignee: Individual
•
Filing: 1978-07-27
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Granted: 1981-01-06
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Expires: 1998-07-27
Abstract
Abstract Control device responding to current changes in a load circuit including a supervisory circuit carrying a current proportional to the current in the load circuit, a transformer coupling the supervisory circuit to the load circuit, and an overcurrent sensor and an overcurrent relay electrically connected in series in the supervisory circuit. The overcurrent sensor being set to deliver a signal when a given first current value is reached after a response delay, the overcurrent relay being able to interrupt the load circuit if a given second current value is reached after an adjustable response delay, and a method of operating the control device in a waste crushing machine.
Inventors
- 👤 Emil Brehm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:15
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/085; H02H3/00; H02H3/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
Method of operating a control device in a waste crushing machine, which comprises switching a drive motor from forward to reverse rotation by actuating a second overcurrent relay of a pair of overcurrent relays connected in series in a supervisory circuit coupled to the load circuit of the motor, after pausing to disconnect the motor from its source when a given first current value is reached, and switching the drive motor to forward rotation after a predetermined duration of reverse rotation and again pausing to disconnect.
Claim 2
Dependent Claim
86 words
Method of operating a control device in a waste crushing machine, which comprises switching a drive motor from forward to reverse rotation by actuating a second overcurrent relay of a pair of overcurrent relays connected in series in a supervisory circuit coupled to the load circuit of the motor, after pausing to disconnect the motor from its source when a given first current value is reached, and switching the drive motor to forward rotation after a predetermined duration of reverse rotation and again pausing to disconnect.
Claim 3
Dependent Claim
72 words
Method according to claim 1, which comprises controlling switching from forward to reverse and from reverse to forward rotation by a current pulse relay having a pair of double-throw contacts, adjusting the disconnect pauses to the fall-back time of the second overcurrent relay, and determining the predetermined duration of reverse rotation by a first time delay relay simulating an overcurrent at the second overcurrent relay at the end of the time delay.
Claim 4
Dependent Claim
30 words
Method according to claim 1 which comprises setting both overcurrent relays to a response delay which is longer than the duration of the switching-on transient current of the drive motor.
Claim 5
Dependent Claim
103 words
Method according to claim 2 which comprises beginning excitation of a second time delay relay when the drive motor is switched on, setting a response time therein which is longer than the predetermined duration of reverse rotation, subsequently delivering a signal with the second time delay relay to switch the drive motor off, activating a third time delay relay at the start of forward rotation of the drive motor, setting a response time therein which is shorter than that of the second time delay relay, and subsequently delivering a signal with the third time delay relay to de-activate the second time delay relay.
Claim 6
Dependent Claim
46 words
Method according to claim 4 which comprises setting the response time of the second time delay relay to more than five times the predetermined duration of reverse duration, and setting the response time of the third time delay relay to the predetermined duration of reverse rotation.
Claim 7
Dependent Claim
41 words
Method according to claim 1, which comprises selectably switching the drive motor off after an adjustable length of time and switching the drive motor into reverse rotation after an adjustable length of uninterrupted forward rotation time with a time delay switch.
Claim 8
Dependent Claim
28 words
Method according to claim 1, which comprises adjustably delaying disconnection of the motor if a second current value which is greater than the first current value is reached.
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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) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |