Electrical switching apparatus with improved contact arm carrier arrangement

Electrical switching apparatus comprising:

• a housing;
• and
• at least one pole comprising:
• a first conductor having at least one stationary contact mounted in said housing;
• at least one elongated contact finger having a movable contact;
• a contact carrier having a pivot pin on which said at least one contact finger is rotatably mounted;
• means mounting said contact carrier for movement between a closed position in which said movable contact engages said stationary contact and an open position in which the movable contact is spaced from the fixed contact;
• contact springs mounted in said contact carrier and biasing said at least one contact finger about said pivot pin to apply contact pressure to said movable contact with said contact carrier in said closed position;
• said at least one contact finger having a pivot aperture through which said at least one contact finger is pivotally mounted on said pivot pin and having a radial convex surface centered on said pivot aperture, and said contact carrier having a radial concave surface on which said radial convex surface on said at least one contact finger seats to transfer into said contact carrier reaction forces exerted on said at least one contact finger with said contact carrier in said closed position and tending to bend said pivot pin;
• a plurality of said contact fingers rotatably mounted in spaced parallel relation on said pivot pin and each having said radial convex surface centered on said pivot aperture and which seats on said radial concave surface on said contact carrier;
• and
• adapted for selectable current ratings wherein a selected number of said contact fingers are mounted on said pivot pin for a selected current rating with said selected number being a first number for a maximum current rating and a second number less than said first number for a lower current rating, and including annular spacers equal in number to a difference between said first number and second number mounted on said pivot pin and which annular spacers seat on said radial concave surface on said contact carrier.

Electrical switching apparatus adapted for selected current ratings comprising:

• a housing;
• and
• at least one pole comprising:
• a first conductor having stationary contact means mounted in said housing;
• a selected number of contact fingers for a selected current rating with said selected number being a first number for a maximum current rating and a second number less than said first number for a lower current rating, each of said selected number of contact fingers having a movable contact;
• a contact carrier having seal means forming a first number of grooves equal in number to said first number of contact fingers, and a pivot pin on which said selected number of contact fingers are pivotally mounted in spaced parallel relation in said grooves;
• means mounting said contact carrier for movement between a closed position in which said movable contacts engage said stationary contact means, and an open position in which the movable contacts are spaced from the stationary contact means;
• contact springs mounted in said contact carrier and biasing said selected number of contact fingers about said pivot pin to apply contact pressure to said movable contacts with said contact carrier in said closed position;
• and
• spacers mounted on said pivot pin and received in grooves in said carrier not occupied by said selected number of contact fingers.

Electrical switching apparatus comprising:

• a housing;
• and
• at least one pole comprising:
• a first conductor having stationary contacts mounted in said housing;
• a plurality of elongated contact fingers each having a first end, a second end, a pivot aperture intermediate of said first and second ends, a movable arcing toe adjacent to said first end, and a movable main contact between said movable arcing toe and said pivot aperture;
• a contact carrier having a pivot pin on which said elongated contact fingers are rotatably mounted in spaced parallel relation, a stop, and contact springs biasing said second ends of said elongated contact fingers about said pivot pin towards said stop;
• and
• means mounting said contact carrier for movement between a closed position in which said movable main contacts engage said stationary contacts and an open position in which said contact fingers are spaced from said first conductor;
• said stop having a contour against which said second ends of said contact fingers are biased by said contact springs with said contact carrier not in said closed position and which projects selected ones of said contact fingers farther toward said stationary contacts than others of said contact fingers, such that said arcing toes of said selected contact fingers are first to contact said stationary contacts on closing and last to separate on opening.

Electrical switching apparatus comprising:

• a housing;
• and
• at least one pole mounted within said housing and comprising:
• at least one contact finger;
• a contact carrier on which said at least one contact finger is mounted;
• and
• means mounting said contact carrier in said housing for movement over a normal range between an open position and a closed position;
• an operating mechanism;
• and
• connecting means connecting said contact carrier to said operating mechanism for movement thereby between said open and closed positions, said mounting means selectively permitting movement of said contact carrier outside of said normal operating range for engagement and disengagement of said connecting means.