Electromagnetic trip for an electrical apparatus for protection

An electromagnetic trip for an electrical switch apparatus to protect against short circuits, comprising:

• a magnetic yoke;
• a tubular non-magnetic coil form having an axis, said form being open at both ends;
• a control coil wound about said form;
• a fixed core and a movable core housed in opposite ends of said form, the movable core having an upper end projecting outside one end of the form and the fixed core having a lower end projecting out of an opposite end of the form, said lower end having an area of reduced diameter forming a groove in a plane perpendicular to said axis;
• said form, said coil, said fixed core and said movable core forming a preassembled electromagnetic subassembly;
• said yoke including a base and an upper portion parallel to said base, said base and said upper portion being perpendicular to said axis, said base having a lower rectilinear slot and said upper portion having an upper rectilinear slot, said slots being opposite one another and forming a plane perpendicular to the planes of said base and said upper portion;
• a return spring fixed to said upper end positioned outside said yoke;
• wherein said subassembly is received into said yoke by transverse sliding so that said groove is received into said lower rectilinear slot and said upper end of said movable core is received in said upper rectilinear slot.