Abstract: A residential or commercial circuit breaker of the narrow width type, typically having a width of 3/4 inch or 1 inch, is provided with a magnetically permeable slot motor 102 mounted within the case 2 and around both current carrying conductors 8 and 12 for concentrating magnetic repulsive force and boosting the contact separating force.

Abstract: A reduced-size thermal overload relay having a housing (2) that includes three narrow compartments (2k, 2l, 2m) in which are mounted three connector brackets (16,18,20) supporting three flat bimetal members (16j, 18j, 20j). Three narrow cassette heaters (6,8,10) are mounted at the upper part of the housing and held in by a snap-in hold-down device (12) that engages pairs of hooks (6b, 7b) at the lower portions of the heaters. A pushbutton (12a) on the hold-down device extends through a hole (3c) in the front wall of the housing for manual depression to release the heaters for removal. Each bracket (16) is H-shaped having legs (16c, 16d) for mounting it in a housing compartment (2k) and arms (16a, 16b) connected by a platform (16e) to which the upper terminal clip (6d) of the cassette heater is clamped with a screw (16q), the small angles of this platform and terminal clip automatically drawing the flat heater element (6c) into desired spacing with the bimetal member.

Abstract: A pair of springs (14, 22) provide counteracting rotational bias to a movable contact arm (8) pivotally supported on a latched lever (10). A handle (4) is manually operable for reducing the force applied by one spring (22) to effect contact (6a, 8b) opening as a result of force applied by the other spring (14). Current sensing means (28, 34, 28a) are operable to release the latched lever (10) for releasing the pivot point (12) of the movable contact arm (8) whereby both springs (14, 22) work in a common direction to rapidly separate the contacts (6a, 8b). Arc gases are exhausted in the direction of separating movement of the movable contact arm (8) to utilize forces associated with arc gas pressure in a cummulative manner with the forces provided by springs (14, 22) to further increase the contact separation speed.

Abstract: A constant load and constant contact force snap-action switch having a normally-closed movable operate contact on a flipper blade which has a compression strip that snaps through an S-curvature to a reverse buckled state to trip the operate contact open. The flipper blade is coupled through an insulating cap to the leaf spring mounted movable alarm contact to close the latter at the same time. A return spring biased reset lever resets the operate contacts on depression down a first amount, opens the operate contact without closing the alarm contacts on depression down a second amount for stop purposes, and trips the operate contacts open on lifting upwards for test purposes. On reset, lost motion in the coupling cap knocks the alarm contact open if welded. A selector is settable to select any of three functions for the reset lever, (1) reset-stop-test, (2) auto reset stop, or (3) reset test.

Abstract: Current limiting stationary (2) and movable (6) contacts are arranged to provide spaced, parallel oppositely directed current paths therein whereby fault currents generate electromagnetic forces for repelling the movable contact (6) from the stationary contact (2). An electrically resistive arc runner (20) has an arc transfer segment (20a) disposed along the path of movement of the movable contact (6) and is biased at one end (20b) into current carrying engagement with a stop (22) on stationary contact (2). The other end of the transfer segment (20a) is connected through a major length of the arc runner (20) to the stationary contact (2) at a point distinct from stop (22). An arc drawn between the contacts (2, 6) at separation initially passes current to the transfer segment (20a) and the stationary contact (2) through stop (22).

Abstract: A plurality of coil springs (6) are secured to the flat inner surfaces (4a) of a jaw type connector (12) to receive a flat conductor (20, 24) such as a bus bar between the opposed springs, the individual coils of each spring (6) engaging the surfaces of the connector (4) and bus bar (20, 24) to provide a compliant, multiple path electrical connection between the connector and bus bar. The springs are plated with a material having a low interface resistance (Rp) with respect to the resistance of the spring wire (Rw) to minimize the net change in resistance of any individual current path in the event of contact interface breakdown between a spring coil and bus bar or connector, thereby reducing or eliminating harmful damage to the spring.

Abstract: A molded case circuit breaker having a movable contact arm (12) pivotally supported on a operating handle (4) and driven into and out of engagement with a stationary contact (6) by an overcenter toggle spring (28) stretched between the movable contact arm (12a) and a latch lever (14) which is releasable to carry the line of action of the spring (28) overcenter of the movable contact arm (12) to cause automatic separation of the contacts (6,10) in response to operation of a bimetal thermal overload sensing unit (18) and which has a separate magnetic overload current sensing unit (38,40) disposed on the stationary contact support (8) and isolated from the thermal overload current sensing unit (18), the magnetic sensing unit (8) operating to release an insulating wedge member (44) for movement between the circuit breaker contacts (6,10) to separate the contacts independently of the latch trip operating mechanism.

Abstract: A narrow width, molded case circuit breaker having parallel, oppositely directed current paths in a conductive stationary contact support (8c) and a pivoting movable contact arm (12b) to cause separation of the contacts (10, 16) by repelling electromagnetic forces independently of a manual operating mechanism (6, 22) or a trip mechanism (18, 20, 22, 24, 26). An arc runner (8e) integral with the stationary contact support (8) has a slot communicating with a vent opening (2d) in the case for venting the arc gasses through the arc runner and vent opening. Arc plates (42, 44) are oriented parallel to the arc runner (8e) to reduce resistance to movement of the arc therethrough by means of gas pressure. Insulators (14, 52) are disposed over conductive members comprising the parallel current paths on the opposite side of the contacts from the arc runner to impede any tendency toward arc movement in an undesired direction.