US 2025/0157771 A1Published application

Circuit breaker interlock mechanism

AssigneeRockwell Automation Switzerland GmbH

InventorsMarkus Gloor, Sadashiv Pimple, Rahel J. von Arx

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Abstract

The present technology relates to a safety feature of industrial circuit breakers. More specifically, a mechanism is disclosed that prevents a circuit breaker switch from being turned to the off position when contact welds are present. In an embodiment, a circuit breaker includes an interlock component that interfaces with a rotary disk used for switching the device on and off. When no contact welds are present, the circuit breaker may be turned off and the interlock component rotates out of the way of the rotary disk due to linear motion resulting from separation of the contacts. However, when a contact weld exists, the interlock component does not move out of the way because no linear motion occurs due to failure to separate the welded contacts. In such a scenario, the interlock component catches an opposing undercut on the rotary disk preventing it from rotating past the point of interlock.

Claims20

Dependent claims

A circuit breaker comprising:

a switch coupled to a rotary disk, wherein the switch rotates about a first axis, wherein the switch includes:
an on position corresponding to an on mode of the circuit breaker;
an off position corresponding to an off mode of the circuit breaker;
and
a trip position corresponding to a trip mode of the circuit breaker;
the rotary disk comprising a receptacle disposed on a circumferential edge of the rotary disk, wherein the rotary disk rotates in a first plane about the first axis as the switch rotates, and wherein a movement of a linkage assembly is in response to rotation of the rotary disk;
and
an interlock component comprising a hook extending from a circumferential edge of a circular body of the interlock component, wherein the interlock component and hook pivots in the first plane about a second axis parallel to the first axis in response to the movement of the linkage assembly, wherein:
the hook of the interlock component is aligned to interface with the receptacle of the rotary disk in an aligned position;
the hook of the interlock component is not aligned to interface with the receptacle of the rotary disk in an unaligned position;
in a normal operation of the circuit breaker, the interlock component pivots in response to movement of the linkage assembly from the aligned position corresponding to the switch in the on position to the unaligned position corresponding to the switch in the off position;
and
in a tripping operation of the circuit breaker, the tripping operation comprising at least one of a set of moving contacts being welded to one of a set of stationary contacts, in response to rotation of the switch from the on position toward the off position:
the hook of the interlock component remains in the aligned position and interfaces with the receptacle of the rotary disk;
and
the switch stops in the trip position in response to the hook interfacing with the receptacle of the rotary disk.

13 more elements

A circuit breaker, comprising:

a switch;
a rotary disk coupled to the switch, the rotary disk comprising a receptacle;
a linkage assembly coupled to the rotary disk;
a set of moving contacts coupled to the linkage assembly;
and
an interlock component coupled to the linkage assembly, the interlock component comprising an interlocking hook, wherein:
in a healthy state of the circuit breaker:
the switch rotates from an on position corresponding to an on mode of the circuit breaker to an off position corresponding to an off mode of the circuit breaker;
in response to the rotation of the switch, the rotary disk rotates with the switch;
in response to the rotary disk rotating, the linkage assembly moves from a first position corresponding to the on mode of the circuit breaker to a second position corresponding to the off mode of the circuit breaker;
in response to the linkage assembly moving from the first position to the second position, the set of moving contacts disengage from a set of stationary contacts;
and
in response to the linkage assembly moving from the first position to the second position, the interlock component rotates from an aligned position to an unaligned position;
and
in an unhealthy state of the circuit breaker, the unhealthy state comprising at least one of the set of moving contacts being welded to one of the set of stationary contacts:
the switch rotates from the on position toward the off position;
in response to the rotation of the switch, the rotary disk rotates with the switch;
in response to the at least one of the set of moving contacts being welded to the one of the set of stationary contacts:
the linkage assembly remains in the first position;
the set of moving contacts remains engaged with the set of stationary contacts;
and
the interlock component remains in the aligned position;
as the switch rotates toward the off position, the interlocking hook of the interlock component engages with the receptacle of the rotary disk;
and
in response to the interlocking hook engaging with the receptacle, the switch does not rotate past a trip position between the on position and the off position.

22 more elements

A method of preventing a switch of a circuit breaker from being turned from an on position to an off position when contacts are welded together, the method comprising:

rotating the switch of the circuit breaker in a first direction from the on position toward the off position, wherein the switch is coupled to a rotary disk comprising a receptacle configured to engage with an interlocking hook of an interlock component of the circuit breaker when the interlock component is in an aligned position;
when the contacts are welded together, preventing the switch from being turned past an intermediary interlock position between the on position and the off position such that the switch cannot reach the off position, wherein preventing the switch from being turned past the intermediary interlock position comprises:
while the switch is rotated in the first direction from the on position toward the off position, stopping rotation of the rotary disk by engaging the receptacle of the rotary disk with the interlocking hook of the interlock component;
and
stopping, via the interlocking hook, the rotary disk at a point of interlock, wherein the point of interlock corresponds to the intermediary interlock position of the switch;
and
when the contacts are not welded together, enabling the switch to be turned from the on position to the off position by:
moving, by the rotary disk, a linkage assembly coupled to the rotary disk in a direction that separates moving contacts of the contacts from stationary contacts of the contacts, wherein the moving contacts are coupled to the linkage assembly;
and
pulling, by one or more springs, a distal end of the interlock component coupled to the linkage assembly out of the aligned position to misalign the interlock component such that the interlocking hook does not engage with the receptacle of the rotary disk at the point of interlock.

7 more elements

Dependencies are inferred from the claim text.