ELEVATOR APPARATUS

• US 20100170751A1
• Filed: 07/25/2007
• Published: 07/08/2010
• Est. Priority Date: 07/25/2007
• Status: Active Grant

• Current Assignee: Murolet IP LLC
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Hashimoto, Jun, Ueda, Takaharu
• Granted Patent: US 8,316,996 B2
• Time in Patent Office: Days
• US Class Current: 187/288
• CPC Class Codes: B66B 1/32 effective on braking devices , e.g. acting on electrically controlled brakes brake control H02P, lift brakes per se B66B5/02
• CPC Class Codes: B66B 5/027 to permit passengers to leave an elevator car in case of failure, e.g. moving the car to a reference floor or unlocking the door

Abstract

In an elevator apparatus, a rescue operation for a car is performed by a rescue operation controller. The rescue operation controller obtains a rescue operation voltage value and applies a voltage having the rescue operation voltage value to a brake coil in response to a signal from a speed detector at a time of the rescue operation for the car. The rescue operation voltage value is a value of the voltage necessary to reduce braking force of a brake device to move the car by using a state of imbalance between the car and a counterweight.

Claims

1. An elevator apparatus, comprising:

a car and a counterweight, each being suspended by a suspending member in a hoistway;

a brake device including a brake coil for canceling braking force by excitation thereof, the brake device being for braking the car against a state of imbalance between the car and the counterweight;

a speed detector for detecting a speed of the car; and

a rescue operation controller for obtaining a rescue operation voltage value corresponding to a value of a voltage necessary to reduce the braking force of the brake device to move the car by using the state of the imbalance between the car and the counterweight and for applying a voltage having the rescue operation voltage value to the brake coil in response to a signal from the speed detector at a time of a rescue operation for the car.

2. An elevator apparatus according to claim 1, further comprising a weighing device for detecting a load in the car,

wherein the rescue operation controller obtains the amount of the imbalance between the car and the counterweight based on a signal from the weighing device to obtain the rescue operation voltage value based on the amount of the imbalance at the time of the rescue operation for the car.

3. An elevator apparatus according to claim 1, wherein the rescue operation controller gradually increases the value of the voltage applied to the brake coil and monitors starting of the car to set the value of the voltage at which the car is started as the rescue operation voltage value at the time of the rescue operation for the car.

4. An elevator apparatus according to claim 1, wherein the rescue operation controller excites the brake coil when the speed of the car is less than a target speed and stops excitation of the brake coil when the speed of the car becomes equal to or higher than the target speed at the time of the rescue operation for the car.

5. An elevator apparatus according to claim 1, wherein the rescue operation controller excites the brake coil when the speed of the car is less than a target speed and reduces a time ratio for exciting the brake coil when the speed of the car becomes equal to or higher than the target speed at the time of the rescue operation for the car.

6. An elevator apparatus according to claim 1, wherein the rescue operation controller excites the brake coil when the speed of the car is less than a target speed and sets the voltage, at which the brake coil is excited, lower than the rescue operation voltage value when the speed of the car becomes equal to or higher than the target speed at the time of the rescue operation for the car.