An exterior operating handle is mounted on the wall of the enclosure of an enclosed-type circuit breaker and is drivingly connected to the operating handle of the circuit breaker. The cover is normally latched in closed position by a manually operable latch. Interlock means normally interlock the exterior handle, cover, and enclosure wall in a manner such that (a) when the cover is latched closed, the exterior handle can be operated to open and close the circuit breaker contacts, selectively; (b) when the cover is unlatched and the exterior handle in in ON position, the interlock means becomes operative to prevent opening of the cover; and (c) when the cover is unlatched or open and the exterior handle is in OFF position, the interlock becomes operative to prevent moving the exterior handle to ON position. If the contacts of the circuit breaker become welded together in closed position while the exterior handle is in ON position, and the exterior handle is moved manually to OFF position and the cover is then unlatched, the interlock means, which normally prevent moving the handle to ON position while the cover is unlatched, are defeated for an instant so as to permit the exterior handle to return automatically to ON position, thus preventing a false indication, and then become active again to interlock the cover and enclosure with the exterior handle in ON position.
A switch device characterized by a switch structure within an enclosure having an openable cover and having interlock means between the switch structure and a handle on the cover for preventing opening of the cover if the contacts of the switch structure are welded in the closed-circuit position.
A circuit interrupter with an interlocking system is provided with stored energy overcenter spring operating means for operating the interrupter between open and closed positions. A latch device latches the operating means in charged positions for the opening and closing operations. An interlocking system provides adequate safety to operating personnel by rendering the latch device inoperable when an enclosure door is opened, or to prevent opening of the door when the interrupter is in the closed position.
A power switch disabler (10) for disable a power switch (12) provided for the energization and de-energization of electrical equipment contained within a housing (18). The power switch disabler (10) includes a housing (18) provided with an access opening (20) and associated access door (22). The access door (22) is provided with a latch (24) for securing the door (22) in a closed position. A pivoting arm (26) is fixed to one end a pivot pin (30) on the outside of the housing (18), and an engagement arm (36) is fixed to a second end of the pivoting pin (30) on the interior of the housing (18). One end of the engagement arm (36) is configured such that when the latch (24) is moved to the locked position, unselected opening of the access door (22) will be prevented. A switch (12) which incorporates a defeat lever (14) is provided for the energization and de-energization of at least one electrical component protected by the housing (18). A switch enabler (51) is provided for engaging the defeat lever (14) for selectively enabling and disabling the switch (12). The switch enabler (51) is connected between the engagement arm (36) and the defeat lever (14) such that as the latch (24) is opened, the switch (12) will be disabled, and as the latch (24) is closed, the switch (12) will be enabled.
A fuse access door of a fusible switch enclosure is held closed by a latch slidably mounted thereto. A resilient interlock actuator secured to the door cooperates with a defeatable switch interlock arm to enable switch closure only while the door is closed and to interlock the latch against unlatching movement while the switch is closed. However, depression of the interlock arm via the interlock actuator defeats this interlock to permit access to the fuses while the switch is closed.
An electric switch mounted within an enclosure having a hinged cover is manually operated from outside the enclosure by a handle mechanism secured to the enclosure. The cover is provided with a single aperture near the edge thereof remote from the cover hinges, with this aperture providing clearance for the operating handle and housing of the mechanism when the cover is closed and also providing clearance for a catch which holds the cover closed. A defeatable cover interlock prevents opening of the cover when the switch is closed, and a defeatable switch interlock prevents closing of the switch when the cover is open. The cover interlock includes a catch and means biasing the catch to cover holding position. When the cover is open, holding means operate and maintain the catch in cover releasing position to permit slamming of the cover without damaging the catch. Rotatable tool operated means on the handle mechanism also locks the cover closed.
