Safety device for elevator
First Claim
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1. A safety device for use in an elevator in which an inverter controls the operation of an electric motor for winding up a cage thereof, said safety device comprising:
- harmonic wave component detecting means for detecting a harmonic wave produced by said inverter; and
means for producing an emergency stop instruction when said harmonic wave component detected by said harmonic wave component detecting means exceeds a predetermined reference voltage.
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Abstract
A safety device for an elevator which detects a trouble of the control device quickly to apply an emergency brake, thereby to ensure the safety of the people in the cage. The elevator safety device is so designed that the harmonic wave component produced by an inverter is detected with the aid of a band-pass filter, and when the harmonic wave component thus detected becomes abnormal, an emergency stop instruction is produced.
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Citations
4 Claims
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1. A safety device for use in an elevator in which an inverter controls the operation of an electric motor for winding up a cage thereof, said safety device comprising:
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harmonic wave component detecting means for detecting a harmonic wave produced by said inverter; and means for producing an emergency stop instruction when said harmonic wave component detected by said harmonic wave component detecting means exceeds a predetermined reference voltage. - View Dependent Claims (2, 3, 4)
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Specification