Aircraft circuit breaker with manual opening resistant feature

A circuit breaker having a manual opening resistant feature comprising:

• a housing,
• at least one stationary electrical contact mounted in the housing,
• a movable contact assembly having at least one movable electrical contact movable between open and closed contacts positions with the at least one stationary electrical contact,
• a movable plunger attached to the movable contact assembly,
• a bushing extending from the housing and having an open end,
• a generally cylindrical pushbutton having a longitudinal axis and having a top surface slidingly received in the bushing and operatively connected to the plunger, the pushbutton movable between a first depressed position generally even with the open end of the bushing and a second outward position extending out of the open end, and
• a pair of diametrically opposed generally L-shaped slots formed in the pushbutton, the slots having a selected width, each slot having a first portion extending in a direction generally parallel to the longitudinal axis of the pushbutton from the top surface thereof and a second arc shaped portion extending along a common circumferential direction, both second portions lying in planes generally perpendicular to the longitudinal axis with the upper surface defining the arc shaped portion forming a reaction surface displaced from the first portion of the respective slot.

A circuit breaker having a manual opening resistant feature comprising:

• a housing,
• at least one stationary electrical contact mounted in the housing,
• a movable contact assembly having at least one movable electrical contact movable between open and closed positions with the at least one stationary electrical contact,
• a movable plunger attached to the movable contact assembly and formed with a reaction surface, selected downward movement of the plunger causing a tripping of the circuit breaker from a closed contacts position to an open contacts position,
• a bushing extending from the housing and having an open end,
• a generally cylindrical pushbutton having a longitudinal axis and having an end wall with a top surface slidingly received in the bushing, the pushbutton movable between a first depressed position generally even with the open end of the bushing and a second outward position extending out of the open end, and
• a relatively small aperture defined in the end wall through the top surface aligned with the reaction surface on the movable plunger.