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US 2010/0300813 A1Published application
Safety device for elevator and rope slip detection method
AssigneeMitsubishi Electric Corporatioin
InventorsHiroshi Kigawa, Naoyuki Maruyama
Life of this patent
Estimating the term…
Abstract
In a safety system for an elevator, slip detection means detects a slip between a drive sheave and a main rope. A safety gear is mounted to a car, the safety gear being electrically operated by an actuator to cause the car to make an emergency stop regardless of whether a running direction of the car is upward or downward. A safety gear controller cuts power supply to a hoisting machine motor and causes the safety gear to make a braking operation upon detection of the slip between the drive sheave and the main rope by the slip detection means.
Claims7
A safety system for an elevator, comprising:
- slip detection means for detecting a slip between a drive sheave and a main rope;
- a safety gear mounted to a car, the safety gear being electrically operated by an actuator to cause the car to make an emergency stop regardless of whether a running direction of the car is upward downward;
- and
- a safety gear controller for cutting power supply to a hoisting machine motor and causing the safety gear to make a braking operation upon detection of the slip between the drive sheave and the main rope by the slip detection means,
- wherein the slip detection means comprises:
- a drive sheave rotation detector for generating a signal according to rotation of the drive sheave;
- and a slip detection circuit for judging occurrence of the slip between the drive sheave and the main rope based on the signal from the drive sheave rotation detector, and
- the slip detection circuit judges the occurrence of the slip between the drive sheave and the main rope when a signal obtained by converting an output from the drive sheave rotation detector into an acceleration exceeds a predetermined deceleration in a case where a brake operation command is issued from a travel controller for controlling a travel of the car.
5 more elements
2-3. (canceled)
A safety system for an elevator comprising:
- slip detection means for detecting a slip between a drive sheave and a main rope;
- a safety gear mounted to a car, the safety gear being electrically operated by an actuator to cause the car to make an emergency stop regardless of whether a running direction of the car is upward or downward;
- and
- a safety gear controller for cutting power supply to a hoisting machine motor and causing the safety gear to make a braking operation upon detection of the slip between the drive sheave and the main rope by the slip detection means,
- wherein the slip detection means comprises a slip detection circuit for judging occurrence of the slip between the drive sheave and the main rope when a rate of reduction of a motor torque of the hoisting machine motor becomes larger than a predetermined value during normal running of the car.
2 more elements
A safety system for an elevator, comprising:
- slip detection means for detecting a slip between a drive sheave and a main rope;
- a safety gear mounted to a car, the safety gear being electrically operated by an actuator to cause the car to make an emergency stop regardless of whether a running direction of the car is upward or downward;
- and
- a safety gear controller for cutting power supply to a hoisting machine motor and causing the safety gear to make a braking operation upon detection of the slip between the drive sheave and the main rope by the slip detection means,
- wherein the slip detection means comprises:
- a temperature measuring device for generating a signal according to a temperature of a surface of the drive sheave and a surface of the main rope, the surfaces being brought into contact with each other;
- and a slip detection circuit for judging occurrence of the slip between the drive sheave and the main rope based on the signal from the temperature measuring device.
4 more elements
A method of detecting a rope slip for an elevator, comprising:
- monitoring an acceleration signal obtained by converting an output from a drive sheave rotation detector for generating a signal according to rotation of a drive sheave into an acceleration when a brake operation command is issued from a travel controller for controlling a travel of a car;
- and
- detecting occurrence of a slip between the drive sheave and a main rope by detecting that a value of the acceleration signal exceeds a predetermined deceleration.
A method of detecting a rope slip for an elevator, comprising:
- monitoring a rate of reduction of a motor torque of a hoisting machine motor during normal running of a car;
- and
- detecting occurrence of a slip between a drive sheave and a main rope by detecting that the rate of reduction becomes larger than a predetermined value.
A method of detecting a rope slip for an elevator, comprising:
- monitoring a signal from a temperature measuring device for generating a signal according to a temperature of a surface of a drive sheave and a surface of a main rope, the surfaces being brought into contact with each other, to detect occurrence of a slip between the drive sheave and the main rope.
Dependencies are inferred from the claim text.