Abstract: The invention relates to a method for turning a pair of wheels in a crane (1) moving on rubber-tired wheels or the like. The crane comprises an electric motor (28) with gearing (16), the electric motor functioning as traversing gear. When the wheels of the crane are turned, the locking device (15) prevents the wheels from turning is released, the crane is driven by the desired angle, and the locking device (15) preventing the wheels from turning is locked. Only one of the wheels (4a) in the pair of wheels is affected by the traversing gear of the crane, the other wheel (4b) being allowed to rotate freely.

Abstract: The invention relates to a system for directing an apparatus, such as a crane bridge (1), moving on wheels along rails, which apparatus comprises a specified drive arrangement (m.sub.1, m.sub.2, m.sub.3, m.sub.4 ; k.sub.1, k.sub.2) on both sides of a roadway defined by rails (3), and which system comprises in the apparatus at least on one side of the roadway at least two successive detectors (d.sub.1, d.sub.2) in the direction of the rail (3) for measuring a lateral distance (l.sub.1, l.sub.2) of a specific part of an edge (e.sub.1, e.sub.2) of the apparatus to be driven from the rail, a control loop (CS) guiding the drive arrangements, a controller of the loop being able to direct the distance measurements (l.sub.1, l.sub.2) of the detectors (d.sub.1, d.sub.

Abstract: The invention relates to an arrangement for controlling a loading element of a crane, the loading element of the crane including an actuator and a current supply cable for supplying current to the loading element. The arrangement for controlling the loading element including a control signal generator/transmitter for generating and transmitting control signals for controlling the actuator of the loading element, a control signal receiver for receiving the control signals in the loading element and a transmission path for transmitting the control signals from the control signal generator/transmitter to the control signal receiver. The transmission path for transmitting the control signals is provided in the current supply cable of the loading element.

Abstract: A method and apparatus for controlling a loading element suspended from lifting drums of a crane by lifting ropes, and a load attached to the loading element. The controlling referring to damping horizontal sway and skew of the loading element and precision positioning the same in the horizontal direction and in the direction of skew by use of a control apparatus comprising control mechanisms mounted in the crane and provided with motors, and four auxiliary ropes between the control mechanisms and the loading element The method comprising the loading element by moving the auxiliary ropes by means of control mechanisms.

Abstract: The invention relates to a traversing gear arrangement for a crane moving on rubber-tired wheels or the like. The crane having an electric motor functioning as the traversing gear and including gearing and wheels arranged in pairs. The wheels in each of the pairs of wheels are connected to each other by a hollow pipe shaft such that one of the wheels is a drive wheel, while the other is a free wheel. The traversing gear connected to the drive wheel is mounted inside the pipe shaft.

Abstract: A procedure for moving the main girder (3) and trolley (2) of a crane uses a gantry part (6) with its bracing structures and a traversing machinery with traversing ropes (4), the traversing machinery being mounted in conjunction with the gantry part. According to the procedure, the trolley is moved by the same traversing machinery as the main girder. When the main girder (3) is to be moved, the trolley (2) is interlocked so that it remains immovable with respect to the gantry (6) and the traversing movement is performed by winding one of the traversing ropes (4a or 4b) onto the winding drum (1) of the traversing machinery and at the same time unwinding the traversing rope (4b or 4a) on the opposite side from the winding drum (1). When the trolley (2) is to be moved, the trolley interlock is released and the traversing movement is performed in the manner described above.

Abstract: The invention relates to an apparatus and a procedure for mounting a bearing wheel journal box (6) in a supporting structure. The supporting structure consists of a supporter side plate (4) having a seating (21) for the journal box (6). The seating has an opening delimited by corners (23,25). On the periphery of the journal box (6) there is an area (12) of reduced thickness, in the region of which the outer measure (S) of the journal box is smaller than the distance (W) between the corners (23,25) of the seating (21), while at other points the outer measure (D) of the journal box is larger than said distance (W). The journal box (6) is inserted into the seating (21) by holding the reduced-thickness portion (12) against the edge (23) of the opening and then turned into a desired position in the seating (21).

Abstract: The invention relates to a procedure and an apparatus for adjusting the speed of an induction machine (1) fed by a frequency converter or an inverter (2) to a value corresponding to a reference value (f.sub.R). In the procedure, a frequency signal (n.sub.m) depending on the actual speed of the motor is generated and the reference value (f.sub.R) Of the motor speed is corrected by means of a correction signal (C) proportional to the slip of the motor. The corrected reference value is used as a frequency reference (f.sub.S) for the frequency converter or inverter. According to the invention, the correction signal (C) proportional to the slip is generated with the aid of the frequency signal (n.sub.m) depending on the actual motor speed and another frequency signal (n.sub.s ') formed from the frequency reference (f.sub.s) of the inverter. When the motor speed changes, e.g. due to variation in the load, the reference frequency of the inverter is corrected correspondingly.

Abstract: A safety mechanism for preventing a cable drum to rotate with overspeed has parallel ratchet wheels which encircle a brake drum. At a periphery of the ratchet wheels are stopping slots wherein a latching pawl is inserted when an overspeed is detected. The slots of the adjacent ratchet wheels are staggered. Thus the braking effect of each ratchet wheel starts at a different point of time.