Abstract: Shaft assemblies include an elongate shaft having a plurality of closely spaced apart external notches with wall segments having a greater outer diameter than an outer diameter of the notches residing therebetween and at least one self-retaining locking ring that engages one of the notches to axially lock into position on the shaft and provide a pull out force that is between about 100 lbf to about 1000 lbf. The notches can have a width that is between about 0.010 inches to about 0.020 inches, on average, and a depth that is between about 0.001 inches to about 0.010 inches, on average.

Abstract: Shaft assemblies include an elongate shaft having a plurality of closely spaced apart external notches with wall segments having a greater outer diameter than an outer diameter of the notches residing therebetween and at least one self-retaining locking ring that engages one of the notches to axially lock into position on the shaft and provide a pull out force that is between about 100 lbf to about 1000 lbf. The notches can have a width that is between about 0.010 inches to about 0.020 inches, on average, and a depth that is between about 0.001 inches to about 0.

Abstract: Shaft assemblies include an elongate shaft having a plurality of closely spaced apart external notches with wall segments having a greater outer diameter than an outer diameter of the notches residing therebetween and at least one self-retaining locking ring that engages one of the notches to axially lock into position on the shaft and provide a pull out force that is between about 100 lbf to about 1000 lbf. The notches can have a width that is between about 0.010 inches to about 0.020 inches, on average, and a depth that is between about 0.001 inches to about 0.010 inches, on average.

Abstract: Shaft assemblies include an elongate shaft having a plurality of closely spaced apart external notches with wall segments having a greater outer diameter than an outer diameter of the notches residing therebetween and at least one self-retaining locking ring that engages one of the notches to axially lock into position on the shaft and provide a pull out force that is between about 100 lbf to about 1000 lbf. The notches can have a width that is between about 0.010 inches to about 0.020 inches, on average, and a depth that is between about 0.001 inches to about 0.

Abstract: An improved circuit breaker having an improved shield apparatus provides protection to components that are internal to the circuit breaker during an arc event. A contact arm carrier assembly of the circuit breaker comprises a number of springs that bias a number of movable contacts that are disposed on contact arms into engagement and electrical connection with a stationary contact. The shield apparatus is disposed on a carrier housing of the contact arm carrier assembly and is situated adjacent the springs. A shield member of the shield apparatus is biased into engagement with the contact arms. When the circuit breaker is moved between the ON position and the OFF or TRIPPED positions, the shield of the shield apparatus moves between a retracted position and a deployed position, with the shield remaining in engagement with the contact arms and protecting the springs from damage in an arc event. In one embodiment, the shield member is formed of a material that generates gases when struck by an arc.

Abstract: An improved circuit breaker having an improved shield apparatus provides protection to components that are internal to the circuit breaker during an arc event. A contact arm carrier assembly of the circuit breaker comprises a number of springs that bias a number of movable contacts that are disposed on contact arms into engagement and electrical connection with a stationary contact. The shield apparatus is disposed on a carrier housing of the contact arm carrier assembly and is situated adjacent the springs. A shield member of the shield apparatus is biased into engagement with the contact arms. When the circuit breaker is moved between the ON position and the OFF or TRIPPED positions, the shield of the shield apparatus moves between a retracted position and a deployed position, with the shield remaining in engagement with the contact arms and protecting the springs from damage in an arc event. In one embodiment, the shield member is formed of a material that generates gases when struck by an arc.

Abstract: A spring offset device is structured to extend between a circuit breaker frame assembly and a trip mechanism. The offset device includes an offset member disposed on a trip device banana link, a spring anchor disposed on the frame assembly, and a spring extending between the offset member and the spring anchor. The spring anchor is spaced from the hatchet pin assembly and, preferably positioned so that the longitudinal axis of the spring remains on a single side of a hatchet pin assembly axis as the banana link moves between a closed position, an open position, and a reset position. The offset member and the spring anchor are structured so that, when the hatchet plate is in the closed position, the spring creates an opening force on the hatchet plate biasing the hatchet plate toward the open position, and when the hatchet plate is in the reset position, the spring creates a closing force on the hatchet plate biasing the hatchet plate toward the closed position.

Abstract: A circuit breaker includes a load terminal and a line terminal; a pair of main contacts; a separable pair of arcing contacts; and a moving conductor assembly having a contact carrier mounted for movement between an open position and a closed position to open and close the separable pairs of contacts. The circuit breaker further includes an arc chute and an arc runner electrically connected to a stationary arcing contact and extending toward the arc chute to provide a path for an arc struck between the separable pair of arcing contacts as the separable pair of arcing contacts open with movement of the moving conductor assembly from the closed position. The arc runner has a longitudinal elongated raised ridge generally laterally centered.

Abstract: An electromagnetic blow-open device for a pole of a circuit breaker where the pole has a stationary contact and a movable contact. The movable contact includes contact fingers mounted on a contact carrier. The contacts have an open position and a closed position. The pole further has an associated rotatable pole shaft. The electromagnetic blow-open device includes a collapsible linkage having a rigid position and a changeable position. The collapsible linkage is disposed between, and coupled to, the pole shaft and contact carrier. The collapsible linkage is maintains the stationary contact and the movable contact in the closed position while the collapsible linkage is in the rigid position and to allow the stationary contact and the movable contact to move to the open position when the collapsible linkage is in said changeable position. The electromagnetic blow-open device also includes an actuator arm which is coupled to the collapsible linkage and is responsive to an over-current condition in the pole.

Abstract: The contact fingers of electrical switching apparatus have radial convex surfaces centered on the pivot pins which seat on concave surfaces in the molded contact carrier to transmit bending loads on the pin into the carrier. A seal member which snaps onto the end of the pivot pin has fins which extend between the contact fingers to block flow of arcing gases through the carrier. For lower current ratings, some of the contact fingers are replaced by annular spacers which also transmit bending moments into the carrier and restrict gas flow. A stop ledge on the carrier against which the contact springs bias the contact fingers has a recess which allows the center fingers to project farther toward the stationary contacts so that the arc toes on these fingers are the last to separate on opening and the arc is concentrated on them.