Ramp-arm mechanism to go up and down stairs. Mechanism equipped with several or one arm (5), the first arm is released manually and the subsequent ones are released automatically until the end of the ladder, these arms can be coupled to a rail (27) as shown in Figure 6 or by a chain, this rail (27) in turn is coupled to the vehicle (21) that aims to raise or lower the ladder； these arms unfold in the path that the wheels will follow； the ramp (1) when colliding with the side of the step in case of climbing or hitting the floor of the step in case of lowering is anchored with the step and this ramp (1) is used so that the vehicle (21) with its own Wheels and traction go up or down the step, the arms remain on the steps until the second wheel passes over them and are picked up for later use, as soon as the arm reaches the system area for the arms to fall (25 ) a new arm is released for the next step, these arms follow a rail (27), these arms are deployed in a certain sequence depending on the size of the ladder； when the end of the ladder is reached the last arm uses the sliding wheel (2) to slide on the ground until the lever (11) is operated and the arm is picked up. With this we can go up or down stairs with most wheeled vehicles. Ramp design (1) to reduce the angle of rise or fall represented in figure 3.4, figure 3.5, figure 3.6.Mecanismo con brazo-rampa para subir y bajar escaleras. Mecanismo dotado de varios o un brazo (5), se suelta el primer brazo manualmente y los posteriores se sueltan automáticamente hasta que se acabe la escalera, estos brazos pueden estar acoplado a un raíl (27) como se muestra en la figura 6 o mediante una cadena, este raíl (27) a su vez esta acoplado al vehículo (21) que pretende subir o bajar la escalera； estos brazos se despliegan en la trayectoria que seguirán las ruedas； la rampa (1) al chocar con el lateral del escalón en caso de subida o chocar contra el suelo del escalón en caso de bajada se ancla con el escalón y se aprovecha e
