US 10,789,798 B1 · Diagnostic element for validation of bolt detection of a guard locking switch in a static state

Abstract

An industrial locking switch includes an inductive sensing circuit that uses a non-contact technique to detect when the switch's locking bolt has transitioned to the lock position. The inductive sensing circuit can comprise an inductive coil, a capacitor, and a converter that converts a frequency of a current signal through the inductive coil to a digital frequency value. A controller detects when the locking bolt has advanced to the lock position by monitoring the digital frequency value for frequency shifts indicative of a disturbance of the induction coil's magnetic field by the locking bolt. To validate operation of the inductive sensing system without requiring actuation of the locking bolt, a diagnostic switch connects a diagnostic capacitor to the inductive circuit to simulate the frequency shift caused by the locking bolt, and the inductive sensing system is validated if the expected frequency shift is detected.

Claims20

Dependent claims

A locking switch, comprising:

a solenoid-driven locking bolt configured to engage with an engagement hole of a locking tongue when advanced to a locking position;
and
an inductive sensor system configured to detect that the locking bolt has advanced to the locking position, wherein the inductive sensor system comprises
a tank circuit comprising an inductive coil and a capacitor, the inductive coil oriented to receive the locking tongue when the locking tongue is advanced to the locking position,
a converter configured to convert a frequency of a current signal on the tank circuit to a digital frequency value, and
a master controller configured to generate a lock detection signal in response to determining that a shift in the digital frequency value corresponds to an expected frequency shift of the current signal induced by the inductive coil in response to advancement of the locking bolt;
and
a diagnostic system configured to confirm operation of the inductive sensor system, the diagnostic system comprising a diagnostic capacitor and a diagnostic switch configured to connect the diagnostic capacitor to the tank circuit in parallel with the capacitor.

5 more elements

A system for sensing a position of a locking bolt of an industrial locking switch, comprising:

an inductive circuit comprising an inductive coil and a capacitor electrically connected in parallel, wherein the inductive coil is positioned to receive a locking bolt of an industrial locking switch when the locking bolt is transitioned to a lock position;
a converter configured to convert a frequency of a current signal on the inductive circuit to a digital frequency value;
a master controller configured to generate a bolt detection signal in response to determining that the digital frequency value changes by an amount equal to or substantially equal to a defined frequency shift corresponding to a frequency shift induced by the inductive coil in response to presence of the locking bolt within the inductive coil's magnetic field;
and
a diagnostic system configured to validate operation of the inductive circuit and the converter, the diagnostic system comprising a diagnostic capacitor and a diagnostic switch configured to electrically connect the diagnostic capacitor to the inductive circuit in parallel with the capacitor.

2 more elements

Dependencies are inferred from the claim text.

Diagnostic element for validation of bolt detection of a guard locking switch in a static state

Life of this patent

Diagnostic element for validation of bolt detection of a guard locking switch in a static state

Life of this patent

Abstract

Claims20