Electromechanical rotary latch for use in current interruption devices

An apparatus utilizing an electromechanical rotary latch, the apparatus comprising:

• one or more cores disposed within a housing;
• one or more fixed contacts disposed proximate to the one or more cores;
• a movable contact assembly having a shaft, the movable contact assembly configured to contact the one or more fixed contacts in an untriggered state and to disengage from the one or more fixed contacts in a triggered state;
• and
• a rotary latch that includes one or more cams each mounted for rotation about a respective fixed bushing rigidly coupled to the housing and biased toward the shaft by one or more torsion springs and a rotatable armature disposed proximate to the one or more cores, the rotatable armature including one or more protrusions positioned to bear against and rotate the cams upon rotation of the armature, wherein the armature is biased such that the armature and the one or more cores are separated by a gap;
• wherein in the untriggered position, the one or more cams extend radially inward into a continuous circumferential notch recessed in a body of the shaft, an axial wall of the notch bearing against the cam to mechanically interlock the shaft, which maintains the movable contact assembly in the untriggered state;
• wherein the rotatable armature is configured to rotate toward the one or more cores in response to a magnetic field induced by an electric current in the one or more fixed contacts;
• and
• wherein rotation of the armature via the protrusions causes the one or more cams to rotate about the fixed bushings against the torsion springs and withdraw radially outward from within the circumferential notch of the shaft, which frees the movable contact assembly to transition to the triggered state such that contact with the one or more fixed contacts is broken.

A method of using an electromechanical rotary latch in current interruption devices, the method comprising:

• connecting one or more stationary contacts of a fuse device to an electric circuit, the fuse device including:
• a rotary latch that includes one or more cams each mounted for rotation about a respective fixed bushing and biased toward a shaft by one or more torsion springs;
• a rotatable armature configured to actuate the rotary latch via one or more protrusions on the armature that bear against the cams;
• and
• a movable contact assembly having a shaft with a continuous circumferential notch recessed in a body of the shaft, the movable contact assembly configured to change between a set position that allows current flow through the fuse device and a triggered position which interrupts current flow through the fuse device;
• wherein in the set position, the one or more cams of the rotary latch extend radially inward into the circumferential notch which maintains the movable contact assembly in the set position by mechanical interlock between an axial wall or lip of the notch and the cam;
• applying an electric current in the electric circuit that exceeds a threshold electric current level, wherein the electric current induces a magnetic field in cores causing the armature to rotate and, via the protrusions, rotate the cams about the fixed bushings against the torsion springs to withdraw the cams radially outward from the notch, which frees the movable contact assembly to transition to the triggered position.