Elevator – industrial lift truck – or stationary lift for vehicle – With monitoring – signalling – and indicating means – Monitors operational parameter
Reexamination Certificate
1999-03-26
2001-03-06
Salata, Jonathan (Department: 2837)
Elevator, industrial lift truck, or stationary lift for vehicle
With monitoring, signalling, and indicating means
Monitors operational parameter
C187S288000, C187S290000, C187S291000, C187S287000
Reexamination Certificate
active
06196355
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to a rescue system, and more particularly to a rescue system for trapped passengers in an elevator car.
BACKGROUND OF THE INVENTION
Elevator rescue systems have been implemented for rescuing trapped passengers from machine-roomless elevator systems. One system involves using levers located remotely in a hallway panel. In machine roomless elevator systems, for example, the levers are connected via a cable to a machine brake located on the elevator machine in the hoistway. The inclusion of a lever, cable, machine interface and installation adds significant cost to the elevator system. Further, such a system relies on either a human operator to regulate the elevator speed, or motor shorting circuitry at additional costs. For example, the human operator must repeatedly release and apply the brake in order to move the elevator car either upwardly or downwardly along the hoistway to the nearest safe elevator landing. In so doing, the human operator must be a highly skilled elevator technician or otherwise careful that the brake is not released for a long enough period of time to enable the elevator car to reach a dangerous speed which can cause serious injury during sudden deceleration of the elevator car when the brake is applied.
It is therefore an object of the present invention to provide an elevator rescue system which avoids the above-mentioned drawbacks associated with prior elevator rescue systems.
SUMMARY OF THE INVENTION
In one aspect of the present invention, an elevator rescue system includes a power source of back-up electrical power. A manually-operated, rescue enable switch switchably permits the transmission of electrical power from the power source to a motor brake coil of an elevator car during a rescue operation such that the energized coil releases the motor brake to move the car to a desired landing. A speed detector measures the speed of the elevator car and thereupon generates a speed control signal corresponding to the speed of the car. An overspeed detection circuit has a first input for being actuated when receiving electrical power from the power source, a second input for receiving the speed control signal, and an output for transmitting electrical power to the motor brake coil when the speed control signal is below a predetermined value and for automatically stopping the transmission of electrical power when the speed control signal becomes higher than a predetermined value. A manually-operated brake release switch has an input and an output. The input is coupled to the output of the overspeed detection circuit, and the output is to be coupled to the motor brake coil of the elevator car for transmitting electrical power to release the motor brake when the brake release switch is closed.
In another aspect of the present invention, an elevator rescue system includes a power source of back-up electrical power. A manually-operated, rescue enable switch switchably permits the transmission of electrical power from the power source to a motor brake coil of an elevator car during a rescue operation such that the energized coil releases the motor brake to move the car to a desired landing. A speed detector measures the speed of the elevator car and thereupon generates a speed control signal corresponding to the speed of the car. An overspeed detection circuit has a first input for being actuated when receiving electrical power from the power source when the rescue enable switch is closed, a second input for receiving the speed control signal, and an output for transmitting electrical power to the motor brake coil when the speed control signal is below a predetermined value and for automatically stopping the transmission of electrical power when the speed control signal becomes higher than a predetermined value. A manually-operated brake release switch has an input and an output. The input is coupled to the output of the overspeed detection circuit, and the output is to be coupled to the motor brake coil of the elevator car for transmitting electrical power to release the motor brake when the brake release switch is closed. A door zone indicator displays when the elevator car is generally level with a desired elevator landing.
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Barna Joseph J.
Blackaby Barry G.
Fargo Richard N.
Schroder-Brumloop Helmut
Sirigu Gerard
Otis Elevator Company
Salata Jonathan
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