An overload relay is disclosed in which a single operator coil is controlled for both tripping and resetting. A permanent magnet and a spring make the device bi-stable, so the coil may be unpowered when in the trip and reset states. Energization of the coil overcomes the magnet to allow tripping, while energization in an opposite direction adds to the magnet force to reset the device. An electromagnetic activation path overrides a mechanical activation path for electromagnetic tripping despite attempted manual resetting. The device may be pulse width modulated to reduce power consumption.

A latch-free actuator includes, for example, a movable arm, a first biasing means operable to apply a force to move the movable arm in a first direction, and a yieldable support having a rigid configuration defining a generally straight axis and a flexible configuration defining a non-straight axis. The yieldable support is operable in the rigid configuration to support a compression force along the straight axis due to and countering the first biasing means so that the movable arm is prevented from movement in the first direction, and the yieldable support is operable, by applying a tripping force, to the yieldable support to transition the rigid configuration to the flexible configuration to withdraw support of the compression force and allow the movable arm to be moved by the first biasing means in the first direction.

A safety switch with detection of the end-stroke of the unlocking mechanism adapted to supervise a safety access of a machine or industrial plant comprises a switching device (2) adapted to be associated to the fixed part of an access to be supervised and having switching means (5) adapted to be operatively connected to one or more control and/or service circuits of the plant for the control thereof, an operating device (3) associated to a movable part of the access to interact with the switching means (5) at the time of opening/closing of the access for opening/closing of one or more circuits, an unlocking mechanism (13) housed in the switching device (2) and having an unlocking pin (14) adapted to translate with maximum predetermined stroke from a blocking position of the access to an unlocked position to determine the opening of the switching means (5), means (17) for the detection of the stroke of the unlocking pin (14) comprising a first detector (18) adapted to detect the start of the stroke of the unlocking pin (14) and a second detector (19) adapted to detect the end of the stroke of the unlocking pin (14).

A safety switch with detection of the end-stroke of the unlocking mechanism adapted to supervise a safety access of a machine or industrial plant comprises a switching device (2) adapted to be associated to the fixed part of an access to be supervised and having switching means (5) adapted to be operatively connected to one or more control and/or service circuits of the plant for the control thereof, an operating device (3) associated to a movable part of the access to interact with the switching means (5) at the time of opening/closing of the access for opening/closing of one or more circuits, an unlocking mechanism (13) housed in the switching device (2) and having an unlocking pin (14) adapted to translate with maximum predetermined stroke from a blocking position of the access to an unlocked position to determine the opening of the switching means (5), means (17) for the detection of the stroke of the unlocking pin (14) comprising a first detector (18) adapted to detect the start of the stroke of the unlocking pin (14) and a second detector (19) adapted to detect the end of the stroke of the unlocking pin (14).

A system may include a relay device that includes armatures associated with phases of voltage signals. The system may also include relay coils, such that each relay coil may receive a respective voltage that magnetizes a respective relay coil, thereby causing the respective armature to move from a respective first position to a respective second position. The system may also include a control system that receive an indication that a fault condition is present, identify a first phase of the phases of voltage signals that is expected to be the next phase of the phases to cross zero, and send a signal to the relay device in response to identifying the first phase. The signal is configured to cause a first relay coil of the relay coils to energize or deenergize.

An electromagnetic relay includes: a coil; a housing that supports the coil; a non-movable portion supported by the housing and including a fixed core and a fixed magnetic path defining member; and a movable portion provided to be reciprocally movable along a center axis line of the coil according to an energization state of the coil. The movable portion includes a movable core disposed to face the fixed core along the center axis line. The movable portion integrally has a flange portion protruding in a coil radial direction perpendicular to the center axis line to define a separation distance and/or a facing area in a magnetic gap between the fixed magnetic path defining member and the movable core by abutting against the non-movable portion.

A latching assembly for latching the moving conductor assembly of a circuit interrupter after an opening stroke includes a streamlined latch that omits components commonly prone to damage during latching operations in existing latching assemblies. The disclosed latching assembly comprises a fixed latch block, a driven latch rotatably coupled to the latch block, and a pivoting hammer with a square pin positioned to always be engaged with the driven latch. The latching assembly is structured to be engaged by a switch shaft once an opening stroke is initiated. When the latching assembly engages, the hammer square pin pushes the driven latch into engagement with a shelf formed in the switch shaft, which prevents the switch shaft from rebounding after the opening stroke. Rebounding is further prevented due to the hammer being structured to be biased toward the open state once the driven latch has engaged the switch shaft shelf.

A latching assembly for latching the moving conductor assembly of a circuit interrupter after an opening stroke includes a streamlined latch that omits components commonly prone to damage during latching operations in existing latching assemblies. The disclosed latching assembly comprises a fixed latch block, a driven latch rotatably coupled to the latch block, and a pivoting hammer with a square pin positioned to always be engaged with the driven latch. The latching assembly is structured to be engaged by a switch shaft once an opening stroke is initiated. When the latching assembly engages, the hammer square pin pushes the driven latch into engagement with a shelf formed in the switch shaft, which prevents the switch shaft from rebounding after the opening stroke. Rebounding is further prevented due to the hammer being structured to be biased toward the open state once the driven latch has engaged the switch shaft shelf.

A mechanical latching device of an electromagnetic contactor eliminates a need to adjust a gap between portions mechanically preventing returning of a latch support. A latch support includes a protrusion protruding laterally and formed with a latch surface facing a released side. A rotating member has one end side rotatably supported and the other end side biased toward the protrusion. When the latch support is on the released side, an outer peripheral surface of the other end side contacts with a tip of the protrusion to allow the latch support to be displaced to a closed side. When the latch support is on the closed side, the other end side rotates according to a position of the latch support in a displacement direction, and a tip surface faces the latch surface to mechanically prevent the latch support from returning to the released side at plural positions along the displacement direction.

A mechanical latching device of an electromagnetic contactor eliminates a need to adjust a gap between portions mechanically preventing returning of a latch support. A latch support includes a protrusion protruding laterally and formed with a latch surface facing a released side. A rotating member has one end side rotatably supported and the other end side biased toward the protrusion. When the latch support is on the released side, an outer peripheral surface of the other end side contacts with a tip of the protrusion to allow the latch support to be displaced to a closed side. When the latch support is on the closed side, the other end side rotates according to a position of the latch support in a displacement direction, and a tip surface faces the latch surface to mechanically prevent the latch support from returning to the released side at plural positions along the displacement direction.