Device for the locking of the wheel of a truck on a lane in front of a façade with a loading and unloading platform, with a guide [ extending parallel to and alongside the lane and a carriage movable on the guide with a locking arm that is movable between a starting position, in which the locking arm extends alongside the lane, and an end position, in which the locking arm partially extends above the lane and therein can rest blocking against the wheel of a truck, wherein the guide and the carriage are provided with co-operating locking means [32, 34] for bringing about a locking of the carriage to the guide, wherein the device is provided with means by which, by moving of the locking arm from the starting position to the end position, the locking means are operated, wherein one of the locking means is mounted on an adjusting organ that is movably provided onto the carriage and which has one or more unevennesses [33b, 35b, 49b] provided in the surface of a part thereof, which co-operate with one or more unevennesses [33a, 35a, 49a] provided in the surface of a part of the locking arm, such, that by a moving of the locking arm the one or more unevennesses [33a, 35a, 49a] provided onto the locking arm are moved over the one or more unevennesses [33b, 35b, 49b] provided onto the adjusting organ, as a result of which the adjusting organ is brought into movement, and the locking means mounted to the adjusting organ is brought into the engagement with the locking means provided onto the guide, with at least one spring being provided, which on the one side is mounted to the carriage and on the other side to the adjusting organ, such, that the bringing of the locking means that is mounted onto the adjusting organ in engagement with the locking means that is provided to the guide, takes place under spring force, wherein the adjusting organ comprises a body at the upper side of which the one or more unevennesses [33b, 35b, 49b] are provided, characterized in that, the adjusting organ further is provided with at least one, two, three, or more lead-through openings with a guide pin mounted onto the carriage being led there through, and with respect to which the adjusting organ is movable in a vertical direction. wherein the device is provided with means by which, by moving of the locking arm from the starting position to the end position, the locking means are operated, wherein one of the locking means is mounted on an adjusting organ that is movably provided onto the carriage and which has one or more unevennesses [33b, 35b, 49b] provided in the surface of a part thereof, which co-operate with one or more unevennesses [33a, 35a, 49a] provided in the surface of a part of the locking arm, such, that by a moving of the locking arm the one or more unevennesses [33a, 35a, 49a] provided onto the locking arm are moved over the one or more unevennesses [33b, 35b, 49b] provided onto the adjusting organ, as a result of which the adjusting organ is brought into movement, and the locking means mounted to the adjusting organ is brought into the engagement with the locking means provided onto the guide, with at least one spring being provided, which on the one side is mounted to the carriage and on the other side to the adjusting organ, such, that the bringing of the locking means that is mounted onto the adjusting organ in engagement with the locking means that is provided to the guide, takes place under spring force, wherein the adjusting organ comprises a body at the upper side of which the one or more unevennesses [33b, 35b, 49b] are provided, characterized in that, the adjusting organ further is provided with at least one, two, three, or more lead-through openings with a guide pin mounted onto the carriage being led there through, and with respect to which the adjusting organ is movable in a vertical direction.