Main circuit breaker

A circuit breaker for use in a panelboard having a bus bar to supply electrical power to a load, comprising:

• a pair of contacts adapted to be connected between said bus bar and a load,
• pivot means for pivoting one of said contacts in one direction about a contact axis for engagement with the other contact to extend power from said bus bar to a load and disengaged from said other contact in response to pivoting movement in the opposite direction about said contact axis to interrupt said power to said load,
• an operating assembly having a handle arranged for rotation about a handle axis to control said operating assembly for movement to an ON position in response to rotation of said handle in a respective direction about said handle axis and into an OFF position in response to rotation of said handle opposite said respective direction about said handle axis,
• cam means interconnecting said operating assembly and pivot means in response to movement of said operating assembly to said ON position for pivoting said one contact in said one direction about said contact axis to engage said other contact with said one contact, said cam means interconnecting said operating assembly and said pivot means in response to movement of said operating assembly to said OFF position for pivoting said one contact in said other direction about said contact axis to disengage said one contact from said other contact,
• and spring means effective in response to initial pivoting of said one contact in said one and opposite directions about said contact axis past a predetermined position for thereafter snap actingly pivoting said one contact in the respective one and opposite direction independently of said cam means.

A circuit breaker for use in a panelboard having a bus bar to supply electrical power to a load, comprising:

• a pair of contacts with one of said contacts adapted to be connected to said bus bar,
• pivot means for pivoting the other contact in one direction about a contact axis transverse to the axis of said bar for engagement with said one contact to extend power from said one contact to a load and disengaged from said one contact in response to pivoting movement in the opposite direction about said contact axis to interrupt said power to said load,
• means for sensing the current level passing through said contacts,
• an operating assembly having a handle arranged for pivoting movement about a handle axis to control said operating assembly for movement to an ON position in response to rotation of said handle in a respective direction about said handle axis and into an OFF position in response to rotation of said handle in the opposite said respective direction about said handle axis,
• cam means interconnecting said operating assembly and pivot means in response to movement of said operating assembly in said respective direction for pivoting said other contact in said one direction about said contact axis to engage said other contact with said one contact and interconnecting said cam means and said pivot means in response to movement of said operating assembly opposite said respective direction for pivoting said other contact in said other direction about said contact axis to disengage said other contact from said one contact,
• spring means effective in response to initial pivoting of said other contact in said one and other directions about said contact axis past a predetermined position for thereafter snap actingly moving said other contact in the respective one and other direction independently of said cam means,
• and means controlled by said sensing means for moving said operating assembly from said ON position to a trip position, intermediate said ON and OFF position in response to the sensing of a fault current level passing through said contacts whereby said cam means controls said pivot means to pivot said other contact in said other direction past said predetermined position to disengage said other contact from said one contact.

A circuit breaker for use in a panelboard having a bus bar extending in a vertical plane from either the top or bottom of said panelboard to supply electrical power to a load comprising:

• a pair of contacts with one of said contacts adapted to be connected to said bus bar,
• pivot means for pivoting the other contact in one direction about a contact axis transverse to the axis of said bar for engagement with said one contact to extend power from said one contact to a load and disengaged from said one contact in response to pivoting movement in the opposite direction about said contact axis to interrupt said power and said load,
• means for sensing a fault current passing through said contacts,
• an operating assembly having a handle arranged for pivoting movement about a handle axis transverse to said contact axis and substantially parallel to the longitudinal axis of said bus bar from controlling said operating assembly to move to an ON position in response to rotation of said handle in one direction about said handle axis and to an OFF position in response to rotation of said handle in the opposite direction about said handle axis,
• a cam member rotatable in a selected direction about a last axis parallel to said contact axis and transverse to the longitudinal axis of said bus bar in response to movement of said operating assembly toward said ON position and rotatable opposite said selected direction in response to movement of said operating assembly toward said OFF position,
• radial means interconnecting said cam member and pivot means in response to rotation of said cam member in said selected direction for pivoting said other contact in said one direction about said contact axis to engage said other contact with said one contact and interconnecting said cam member and said pivot means in response to rotation of said cam member opposite said selected direction for pivoting said other contact in said other direction about said contact axis to disengage said other contact from said one contact,
• spring means effective in response to initial pivoting of said other contact in said one and other directions about said contact axis past a predetermined position for thereafter snap actingly moving said other contact in the respective one and other direction independently of said cam member means,
• and last means controlled by said sensing means for moving said operating assembly from said ON position to a trip position intermediate said ON and OFF position in response to the sensing of a fault condition and for indicating the trip condition of said circuit breaker, said last means controlling said cam member together with said radial means to pivot said other contact in said other direction to disengage other contact from said one contact.

A circuit breaker comprising,

• a housing carrying a pair of terminals with one of said terminals adapted to be connected to a source of power and the other terminal adapted to be connected to load,
• a pair of contacts in said housing with one of said contacts connected to said other terminal,
• a blade bracket of relatively high melting temperature supporting the other contact for pivoting movement in one direction to engage said one contact and for pivoting movement in another direction to disengage said other contact from said one contact, said blade bracket includes a U-shaped member having pivotally supported side legs and a back wall secured to said metal and of greater width than said metal with said back wall interposed between said arc and said metal in response to pivoting movement in said other direction,
• a metal of relatively low melting temperature connecting said one terminal to said other contact,
• means for sensing the current level passing through said contacts,
• an operating assembly adapted to be manually controlled to move said blade bracket for moving the other contact to engage said one contact and controlled by said sensing means in response to said sensing means sensing a current above a predetermined value for disengaging said other contact from said one contact,
• and a vent in said housing at a position spaced below said one terminal for venting gases from said housing in the event an arc develops between said contacts with a portion of said blade bracket interposed between said vent and said metal of relatively low melting temperature.

A circuit breaker for use in a panelboard having a bus bar to supply electrical power to a load, comprising:

• a pair of contacts with either one of said contacts adapted to be connected to said bus bar,
• pivot means for pivoting one of said contacts in one direction about a contact axis for engagement with the other of said one contacts to extend power from said bus bar to a load and disengaged from said other contact in response to pivoting movement in the opposite direction about said contact axis to interrupt said power to said load,
• means for sensing the current level passing through said contacts,
• an operating assembly having a handle arranged for pivoting movement about a handle axis to control said operating assembly for movement to an ON position in response to rotation of said handle in an ON direction about said handle axis and into an OFF position in response to rotation of said handle in an OFF direction about said handle axis,
• cam means interconnecting said operating assembly and pivot means in response to movement of said operating assembly in said ON direction for pivoting said one contact in said one direction about said contact axis to engage said one and other contacts and interconnecting said cam means and said pivot means in response to movement of said handle in said OFF direction for pivoting said one contact in said other direction about said contact axis to disengage said one contact from said other contact,
• spring means effective in response to initial pivoting said one contact in said one and other directions about said contact axis past a predetermined position for thereafter snap actingly moving said one contact in the respective one and other direction independently of said cam means,
• trip means controlled by said sensing means for moving said operating assembly from said ON position to a trip position intermediate said ON and OFF position irrespective of the rotation of said handle in said ON direction in response to the sensing of a fault current above a predetermined level passing through said contacts by said sensing means whereby said cam means controls said pivot means to pivot said one contact in said other direction past said predetermined position to disengage said one contact from said other contact,
• and trip indicating means operated in response to the movement of said operating assembly to said trip position for providing a visual signal corresponding to said trip position.