Indicator to show whether a switch has opened
First Claim
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1. A machine comprisingan electric motor and a circuit for energizing the motor;
- a multiplicity of normally closed switches in the circuit for monitoring the operation of the machine any one of which opens in response to the occurrence of an event to shut off the motor and which are capable of reclosing in response to the cessation of the event to place the motor in a condition to restart;
means enabling restarting of the motor upon reclosing of an opened switch; and
means for indicating which of the multiplicity of switches has opened regardless of whether the open switch has reclosed, including a multiplicity of indicators each of which comprises conductive means in circuit with an associated one of the switches in the switch open position which is rendered nonconductive upon opening of its associated switch and upon passage of a given electrical load therethrough and means rendered distinctly different in appearance upon passage of the given electrical load through the conductive means;
each associated switch being arranged in circuit with its associated conductive means for delivering the given electrical load therethrough upon switch opening.
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Abstract
An indicator is provided for use in a machine, such as an escalator, having a multiplicity of normally closed switches which act to turn off the machine in the event of a machine malfunction, unsafe condition or an inappropriate switch placement. The switches are capable of reclosing but not restarting the machine. The indicator shows which of the switches caused the machine to stop thereby performing a troubleshooting function to allow a repairman to determine immediately which of the various machine systems caused the malfunction or unsafe condition.
17 Citations
18 Claims
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1. A machine comprising
an electric motor and a circuit for energizing the motor; -
a multiplicity of normally closed switches in the circuit for monitoring the operation of the machine any one of which opens in response to the occurrence of an event to shut off the motor and which are capable of reclosing in response to the cessation of the event to place the motor in a condition to restart; means enabling restarting of the motor upon reclosing of an opened switch; and means for indicating which of the multiplicity of switches has opened regardless of whether the open switch has reclosed, including a multiplicity of indicators each of which comprises conductive means in circuit with an associated one of the switches in the switch open position which is rendered nonconductive upon opening of its associated switch and upon passage of a given electrical load therethrough and means rendered distinctly different in appearance upon passage of the given electrical load through the conductive means; each associated switch being arranged in circuit with its associated conductive means for delivering the given electrical load therethrough upon switch opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A machine comprising
an electric motor and a circuit for energizing the motor; -
a multiplicity of normally closed switches in the circuit for monitoring the operation of the machine any one of which opens in response to the occurrence of an event to shut off the motor and which are capable of reclosing in response to the cessation of the event to place the motor in a condition to restart; means enabling restarting of the motor upon reclosing of any opened switch; and means for indicating which of the multiplicity of switches has opened regardless of whether the opened switch has reclosed, including a multiplicity of indicators each of which comprises a conductive element in circuit with an associated one of the switches in the switch open position which is rendered nonconductive upon opening of its associated switch and upon passage of a given electrical load therethrough, the conductive element having the characteristic of being rendered distinctly different in appearance upon passage of the given electrical load through the conductive element; each switch being arranged in circuit with its associated conductive element for delivering the given electrical load therethrough upon the switch opening. - View Dependent Claims (18)
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Specification