GB644268A - Improvements in and relating to a.c. motors for cranes and other load raising and lowering apparatuese - Google Patents

Improvements in and relating to a.c. motors for cranes and other load raising and lowering apparatuese

Info

Publication number
GB644268A
GB644268A GB2397148A GB2397148A GB644268A GB 644268 A GB644268 A GB 644268A GB 2397148 A GB2397148 A GB 2397148A GB 2397148 A GB2397148 A GB 2397148A GB 644268 A GB644268 A GB 644268A
Authority
GB
United Kingdom
Prior art keywords
load
brake
motor
controller
current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB2397148A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hardie Smellie & Partners Ltd
JOHN HARDIE SMELLIE
Original Assignee
Hardie Smellie & Partners Ltd
JOHN HARDIE SMELLIE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hardie Smellie & Partners Ltd, JOHN HARDIE SMELLIE filed Critical Hardie Smellie & Partners Ltd
Priority to GB2397148A priority Critical patent/GB644268A/en
Publication of GB644268A publication Critical patent/GB644268A/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C13/00—Other constructional features or details
    • B66C13/18—Control systems or devices
    • B66C13/22—Control systems or devices for electric drives
    • B66C13/23—Circuits for controlling the lowering of the load
    • B66C13/26—Circuits for controlling the lowering of the load by ac motors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C2700/00—Cranes
    • B66C2700/08—Electrical assemblies or electrical control devices for cranes, winches, capstans or electrical hoists
    • B66C2700/081—Electrical assemblies or electrical control devices for cranes, winches, capstans or electrical hoists with ac motors

Landscapes

  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Mechanical Engineering (AREA)
  • Control And Safety Of Cranes (AREA)

Abstract

644,268. Control of A.C. motors. SMELLIE & PARTNERS, Ltd., J. H., and SMELLIE, J. H. Sept. 13, 1948, No. 23971. [Class 38(iii)] A three-phase induction hoist motor A has a controller B in the first hoisting- position of which contactors E and D are closed respectively to energize the stator and to remove an electro-magnetic brake C. Thereafter, the controller is moved to reduce rotor resistance H. When the controller is moved to the first lowering notch a contactor G is closed and the stator is supplied with direct-current through transformer K and rectifier L. The brake is removed, so that the motor rotates under the action of its load at a creeping speed which may be increased by increasing the resistance of the rotor circuit. The motor is driven in the lowering direction when the controller is adjusted to its last lowering notch, the contactor G being opened, all or part of the resistors H being restored to the rotor circuit, and contactor F closed for appropriate energization of the motor stator. If the current generated by the motor when driven by its load becomes excessive, a relay-coil m in the rotor circuit operates a switch M to de-energize the brake contactor coil d. So that, when the load is lowered out of control, the brake is applied to stop the motor and then the coil m is de-energized to remove the brake. The load is then lowered at a speed determined by the position of the controller, and, if control of the load is again lost, the cycle of operations is repeated. The relay m is rendered ineffective during hoisting-operation. To obtain uniform lowering speed with various loads, a transformer P is included in the rotor circuit and rectified current is supplied to coils r1, r2, r3, of relays R1, R2, R3, which control resistor S in the circuit through which direct-current is supplied to the motor stator. The relays R1, R2, R3, are operative at different current-values so that the resistor S is adjusted in accordance with the load. Failure of current passing through relaycoil t opens contact T to apply the brake.
GB2397148A 1948-09-13 1948-09-13 Improvements in and relating to a.c. motors for cranes and other load raising and lowering apparatuese Expired GB644268A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2397148A GB644268A (en) 1948-09-13 1948-09-13 Improvements in and relating to a.c. motors for cranes and other load raising and lowering apparatuese

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2397148A GB644268A (en) 1948-09-13 1948-09-13 Improvements in and relating to a.c. motors for cranes and other load raising and lowering apparatuese

Publications (1)

Publication Number Publication Date
GB644268A true GB644268A (en) 1950-10-04

Family

ID=10204344

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2397148A Expired GB644268A (en) 1948-09-13 1948-09-13 Improvements in and relating to a.c. motors for cranes and other load raising and lowering apparatuese

Country Status (1)

Country Link
GB (1) GB644268A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2121903A (en) * 1982-05-11 1984-01-04 Yngve Eero Connector

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2121903A (en) * 1982-05-11 1984-01-04 Yngve Eero Connector

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