Siemens Aktiengesellschaft

Werner Koziolek

Bernhard Preuss

In the low-voltage circuit breaker that has a toggle lever system connecting the actuating arm to a carrier that moves the movable contact, a locking lever is provided to prevent transfer of the operating lever handle to its 'off' position if the movable contact is welded to the stationary contact. The locking lever is pivoted about a bearing support formed in the housing of the circuit breaker. The opposite end of the locking lever is connected to the handle to be pivoted by it. The locking lever has an angled-off projection that extends into the path of movement of the carrier and is positioned to engage the carrier if the latter is unable to move from its 'on' position due to welding of the contacts together. When the contacts are not welded together, the locking lever enforces the toggle levers to snap through to their 'off' position before the angled-off part of the locking lever comes into contact with the carrier of the movable contact.

Growing community of inventors

Berlin, Germany

Werner Koziolek