Abstract: A safety structure for a hand brake contains: a casing, a body, a roller rotatably, a first brake line, a second brake line, and a third brake line. The first brake line are connected with a first brake and a second brake of a vehicle, and the second brake line is coupled with a first controller on a left handle of the vehicle, the third brake line is coupled with a second controller on a right handle of the vehicle. The first brake line is bent in half and has two shoulders adjacent to the roller, and an outer diameter of each of the two shoulders is more than the first brake line so that when the first brake line is broken, at least one of the two shoulders stops inside the body or the casing, and at least one of the first and second brakes stops the vehicle.

Abstract: A manual brake structure is employed to stop a bicycle or motorcycle and contains: a casing, a body, a roller, a first brake line, a second brake line, and a third brake line. The casing includes a first cap and a second cap. The body is housed in the casing and includes a first accommodation portion and a second accommodation portion having two first apertures. The roller is housed in the first accommodation portion and includes a trench. The first brake line is bent in half, fitted into the trench, and connected with a first brake and a second brake of the bicycle or motorcycle. The second brake line includes a first stop block and couples with a first controller of the bicycle or motorcycle. The third brake line includes a second stop block and couples with a second controller of the bicycle or motorcycle.