Multipolar type circuit breaker

A multipolar type circuit breaker including a plurality of breaker element assemblies for alternating source current poles respectively comprising a fixed contactor having a fixed contact and connected to a source side terminal, a movable contactor supported movably between ON and OFF positions of its movable contactor with said fixed contact, a contact operating mechanism for changing over said movable contactor between said positions, and a trip mechanism interlinked with said operating mechanism to form a current path between the movable contactor and a load side terminal and including means which normally latches the movable contactor at its ON position but releases the latching upon incoming of an excessive current for forcibly tripping the movable contactor out of the ON position,

• said assemblies respectively having a handle link pivoted at one end to a fixed handle supporting shaft and operably connected at the other end to said contact operating mechanism, the respective assemblies being housed in a single housing respectively with said handle supporting shaft and tripping means in alignment with each other, said handle link in each of the assemblies being directly operated by a single handle engaging directly with all the assemblies, and said tripping means in the respective assemblies being interlinked to each other by an interlinking rod engaged to the respective means for transmitting said forcible trip operation in either one of the assemblies synchronously with the means in the other assemblies,
• said handle comprising a main shaft part extending within said housing transversely of said plurality of assemblies while engaging said handle supporting shaft and handle link in the respective assemblies to be axially rotatable about the handle supporting shaft, and a lever part extending from said main shaft part to the exterior of said housing, and said interlinking rod extends within the housing transversely of the assemblies and is supported axially rotatably, said interlinking rod being provided with a plurality of projections respectively engageable with said tripping means in the respective assemblies, said trip mechanism including an excessive current sensing means forming said current path, said tripping means comprising a latch link connected at one end to said contact operating mechanism and having at the other end a latch engaging part, said latch link being rotatably supported substantially at an intermediate position by a fixed shaft, and a tripping lever having at one end a first part engageable with said latch engaging part of said latch link for achieving a latch engagement therewith and at the other end a second part engageable with said sensing means, said tripping lever being rotatably supported substantially at the center about a fixed shaft normally biased toward engagement with the detecting means, said plurality of projections of said interlinking rod respectively comprising a pair of legs, a first one of which extending close to the latch engaging part of the latch link and a second one of which extending close to said first part of the tripping lever, such that a force imparted to either one of said first and second legs by a rotation of either one of the latch link and tripping lever causes the interlinking rod to be axially rotated.