Current limiting device and circuit interrupter having a current limiting function

A circuit interrupter having a current limiting function comprising:

• a movable member having a movable contact and a movable arm and rotatable about a movable member rotary shaft;
• a stationary member having a stationary contact making a contact pair with said movable contact and a stationary conductor substantially opposing said movable arm;
• a tubular insulator adjacent to and circumferentially surrounding said contact pair in a closed state;
• and
• a contact pressure spring providing contacting pressure to said contact pair, said contact pair being positioned within a cylindrical space defined by said tubular insulator in the closed state, and said movable contact being positioned outside of the cylindrical space in an open state so that, upon initial opening of said contact pair in response to an excessive current flow through said movable arm and said stationary conductor, and formation of an arc between said movable contact and said stationary contact, gas pressure at the arc is increased due to gas confinement within said tubular insulator.

A current limiting device comprising:

• a movable member contained within an electrically insulating housing and having a movable contact and an L-shaped movable arm rotatable about a movable member rotary shaft;
• a stationary member having a stationary contact making a contact pair with said movable contact and an electrical path substantially parallel to one portion of said movable arm for flow of an electrical current in a direction opposite current flow in said movable arm upon contact closing;
• a tubular insulator adjacent to and circumferentially surrounding the contact pair in a closed state;
• biasing means for applying contacting pressure to said contact pair;
• an arc extinguishing plate opposing a tip of said movable member;
• and
• terminals disposed on a side of said insulating housing opposite said movable contact and said stationary member, said contact pair, in the closed state, being positioned within a cylindrical space defined by said tubular insulator and, in an open state, said movable contact being positioned outside of the cylindrical space so that, upon initial opening of said contact pair in response to an excessive current flow through said movable member and said stationary member, and formation of an arc between said movable contact and said stationary contact, gas pressure at the arc is increased due to gas confinement within said tubular insulator.