US3633081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling and regulating a cutter hoist
Assignee: Gebr Eickhoff Maschinenfabrik u Eisengiesserei GmbH
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Filing: 1970-06-18
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Granted: 1972-01-04
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Expires: 1990-06-18
Abstract
Abstract Motor control system for a mining machine of the type in which a cutting element is driven by a first electrical motor and the mining machine is advanced into a coal face by a second motor. The system is characterized in that the torque and speed of the second motor are reduced both when the cutter element drive motor is idling as well as when the cutter motor is overloaded. The arrangement is such that as the cutting element approaches the coal seam and is idling, the speed of the advancing drive motor is relatively low; when the cutter enters the coal face and the current to the cutter drive motor increases, the speed of the advancing drive motor is also increased; and when the cutter element drive motor is overloaded, the advancing drive motor is reversed to withdraw the cutting element from the coal face and thereafter again advances the cutting element into the coal face in a pulsing or reciprocating motion.
Inventors
- 👤 Karl Heinz Weber
- 👤 Horst Engelhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:02
CPC Classifications
E; E21; E21C; E21C31/00; E21C31/02; E21C35/00; E21C35/302; H; H02; H02P; H02P29/00; H02P29/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
121 words
In apparatus for controlling a mining machine of the type in which the mining machine is advanced into a coal seam by an advancing electrical drive motor and a coal-cutting element on the mining machine is driven by a cutter drive motor; the combination of motor control means for said advancing drive motor including a current-limiting circuit responsive to current flow through said cutter drive motor for controlling the speed of said advancing motor such that the speed of the advancing motor will be relatively low when the cutting element is removed from a coal face and is essentially unloaded, while the speed of the advancing motor will be increased when the cutting element enters the coal face and is loaded.
Claim 2
Dependent Claim
121 words
In apparatus for controlling a mining machine of the type in which the mining machine is advanced into a coal seam by an advancing electrical drive motor and a coal-cutting element on the mining machine is driven by a cutter drive motor; the combination of motor control means for said advancing drive motor including a current-limiting circuit responsive to current flow through said cutter drive motor for controlling the speed of said advancing motor such that the speed of the advancing motor will be relatively low when the cutting element is removed from a coal face and is essentially unloaded, while the speed of the advancing motor will be increased when the cutting element enters the coal face and is loaded.
Claim 3
Dependent Claim
91 words
The combination of claim 1 wherein said motor control means includes a voltage reference controller for producing an electrical signal proportional to the desired speed of said cutter drive motor, means for comparing said signal proportional to desired motor speed with a signal proportional to actual motor speed to derive an error signal, a voltage regulator responsive to said error signal, said current-limiting circuit being connected to the output of said voltage regulator, and a controllable power supply for said advancing drive motor connected to the output of said current-limiting circuit.
Claim 4
Dependent Claim
24 words
The combination of claim 2 wherein said advancing drive motor is a direct current motor and said cutter drive motor is an alternating-current motor.
Claim 5
Dependent Claim
31 words
The combination of claim 3 wherein said cutter drive motor is connected to a three-phase alternating-current supply which also supplies power to said controllable power supply for said advancing drive motor.
Claim 6
Dependent Claim
43 words
The combination of claim 2 including means responsive to a current surge in said cutting element drive motor or said advancing drive motor for reversing the direction of rotation of said cutter drive motor to withdraw the cutting element from the coal face.
Claim 7
Dependent Claim
26 words
The combination of claim 5 including means for disabling said advancing drive motor after said advancing drive motor is reversed in direction at least two times.
Claim 8
Dependent Claim
46 words
The combination of claim 5 wherein said means responsive to a current surge includes a second current limiter in shunt with said first-mentioned current limiter and is actuable to reverse said cutter drive motor only after said current surge persists beyond a predetermined period of time.
Claim 9
Dependent Claim
73 words
The combination of claim 2 including means in said voltage reference controller for establishing an idling speed for said cutter drive motor, a threshold detector for sensing a rise in current through said cutter drive motor when said cutting element enters a coal seam, and means coupled to the output of said threshold detector for increasing the electrical signal output of said voltage reference controller and the speed of said advancing drive motor.
Claim 10
Dependent Claim
50 words
The combination of claim 2 wherein said current limiting circuit is connected through an OR-circuit to current transformers coupled to power input leads to both said advancing drive motor and said cutter drive motor whereby a current surge in either motor will reduce the speed of said advancing drive motor.
Claim 11
Dependent Claim
16 words
The combination of claim 2 wherein said controllable power supply Is of the reversible thyristor type.
Claim 12
Dependent Claim
53 words
The combination of claim 2 wherein said advancing drive motor is a direct current motor having a field winding supplied with power through a thyristor device, and means for reducing the power supplied to said field winding through said thyristor device where the speed of said advancing drive motor exceeds a predetermined limit.
References Cited (Backward Citations)
US2129049A
Cited
US2809333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |