Remotely controllable circuit breaker with improved arc drive structure

A remotely controllable circuit breaker comprising:

• a housing;
• a breaker contact comprising first and second movable contacts;
• a first contact arm carrying at its one end said first movable contact and movable between an OFF position and an ON position;
• a second contact arm extending generally in parallel relation to said first contact arm and formed with said second movable contact on the same end as said first contact arm;
• a switching mechanism for opening and closing said breaker contact, said switching mechanism including a manual handle connected to move said first contact arm between the OFF position and the ON position, said switching mechanism further including trip means acting to forcibly move said first contact arm toward its OFF position from its ON position in response to an overcurrent flowing through the circuit of the breaker;
• a remotely controllable electromagnet switch operatively connected to said second contact arm to move, in response to a remote control signal, the second contact arm between an operative position where said second contact is permitted to come into contact with said first contact in said ON position and an inoperative position where said second contact is kept away from said first contact to be inhibited from contacting therewith;
• an arc extinguishing chute disposed on the opposite side of said first contact arm from said second contact arm for extinguishing an arc initially developed between the rapidly separating first and second contacts;
• an arc runner electrically coupled to the second contact arm and extending generally along the opening path of said first contact and leading to said arc extinguishing chute for receiving from said second contact the one end of said arc and guiding the arc toward said arc extinguishing chute with said one end of the arc anchored on the surface of the arc runner as the first contact moves to its OFF position;
• an arc drive member extending immediately behind said second contact arm without leaving any substantial part therebetween and in generally parallel relation to said first contact arm with its one end connected to said arc runner, the other end of said arc drive member electrically connected to the end of the second contact arm opposite to said second contact such that the arc drive member and said arc runner constitute a bypass for the arc current across said second contact arm, said arc drive member cooperative upon the occurrence of the arc with the first contact arm to develop in the region therebetween a magnetic field that extends transversely of said arc for producing an electromagnetic repulsion force which acts on the arc to urge it towards said arc extinguishing chute;
• said remotely controllable electromagnet switch disposed in said housing in side-by-side relation to said switching mechanism with said first and second contact arms interposed therebetween;
• said arc drive member extending along a partition wall and electrically isolated thereby from said remote controllable electromagnet switch, said partition wall serving as a barrier for blowing an arc gases resulting from the arc towards said arc chute;
• said second contact arm formed at its end adjacent said second contact with a pilot extension which projects toward said arc runner to leave therebetween a small arc transferring gap;
• said arc extinguishing chute comprising a number of stacked arc shearing plates supported by a holder and provided in its rear wall of said holder opposite to the first contract arm with an escape opening for a volume of ionized gases developed by said arc reacting with its environments;
• said chute disposed within a chamber in said breaker housing with the rear wall of the chute in spaced relation from the corresponding rear wall of said chamber to leave therebetween a rear space through which said escape port opening communicates with an exhaust port formed in the bottom wall of said chamber and leading to the exterior of said breaker housing;
• said chamber formed in its side walls at a portion adjacent the rear wall with a notched space which communicates with said rear space as well as with said exhaust port.