Cable drums

Our program also includes a wide variety of cable drums. The cable drums are fitted with a spring coil or an electric motor for automatic cable winding. The cable is a so-called special drum cable allowing multiple coiling and uncoiling without breaking the conductors. The drum is fitted with a slip ring to provide contact with fixed locations. The number of sliding contacts for control signals may involve 100 or more! For spring coil cable drums, the cable diameter goes up to 35mm² and for motor cable drums up to 300 mm² max. Drums are often used for vertical applications, for instance, for supplying power to lifting tools (magnet, tongs) fitted to the hook of an overhead travel crane. Cable drums are also used for supplying power to indoor and outdoor portal cranes. In such cases, the unwound cable is deposited in a floor gutter preventing it from becoming an obstacle for, for instance, lorries or forklift trucks.

Special applications
At present, various systems are able to transfer bus signals, RS232 / RS485 signals, free of interference, by means of a conductor rail or slip ring unit. It involves using special processor-controlled data amplifiers for fieldbus systems via conductor rails or slip rings. These compensate contact resistance between the copper strip and carbon brush of the user. It also filters certain transfer errors.

The latest technology includes contactless systems for energy and data transfer. In this case, power collector and conductor rail are no longer in physical contact.

Energy transfer involves induction. Both the track and collector form a sort of coil and move alongside one another. Thus forming, as it were, a transformer whereby the energy is transferred from one coil to the other without physical contact.

In the case of data transfer, the principle can be compared to a transmitter-receiver which transmits the signals. These systems are still in their infancy and cannot always be used just like that.

It is obvious that this system, due to lack of physical contact between the parts, is not subject to mechanical wear. At the same it allows for extremely high speeds, the system is silent and can even be employed under water!