Braking device for elevator apparatus, for emergency braking of a cabin that can be moved longitudinally by vertical guides , comprising: - a wedging block attachable to a chassis of the cabin, comprising in turn: - a central slot to house the guide , - a catching element , movable perpendicular to the central slot , and - a braking element movable with respect to the central slot , and attachable to the guide and to the catching element to immobilize the cabin, - an activation electromagnet , and - an articulated actuating mechanism comprising a first sector linked to the electromagnet and a second sector linked to the braking element , wherein the actuating mechanism comprises a friction element , located in the second sector and capable of engaging the guide for fixing a safe position of the cabin on the guide , such that when the actuating mechanism engages the friction element with the guide , and a relative movement of the guide with respect to the cabin occurs, said actuating mechanism moves the braking element in the same direction until it engages the guide , characterised in that the actuating mechanism further comprises: - a first arm , integrally linked to the electromagnet , - a second arm , pivotally linked to the first arm through a first joint , and - a third arm , pivotally linked by a first end to the second arm through a second joint , and linked to the braking element , which it moves, and wherein the friction element is integrally linked to a second end of the third arm ; the friction element is a machining located at the second end of the third arm . - a wedging block attachable to a chassis of the cabin, comprising in turn: - a central slot to house the guide , - a catching element , movable perpendicular to the central slot , and - a braking element movable with respect to the central slot , and attachable to the guide and to the catching element to immobilize the cabin, - a central slot to house the guide , - a catching element , movable perpendicular to the central slot , and - a braking element movable with respect to the central slot , and attachable to the guide and to the catching element to immobilize the cabin, - an activation electromagnet , and - an articulated actuating mechanism comprising a first sector linked to the electromagnet and a second sector linked to the braking element , wherein the actuating mechanism comprises a friction element , located in the second sector and capable of engaging the guide for fixing a safe position of the cabin on the guide , such that when the actuating mechanism engages the friction element with the guide , and a relative movement of the guide with respect to the cabin occurs, said actuating mechanism moves the braking element in the same direction until it engages the guide , characterised in that the actuating mechanism further comprises: - a first arm , integrally linked to the electromagnet , - a second arm , pivotally linked to the first arm through a first joint , and - a third arm , pivotally linked by a first end to the second arm through a second joint , and linked to the braking element , which it moves, and wherein the friction element is integrally linked to a second end of the third arm ; - a first arm , integrally linked to the electromagnet , - a second arm , pivotally linked to the first arm through a first joint , and - a third arm , pivotally linked by a first end to the second arm through a second joint , and linked to the braking element , which it moves, and <EOS>