EoW September 2013

Technical article

Standing close to the take-up involves the risk of being jammed between the product and the reel, with serious personal injuries as a result. As health and safety requirements become more stringent, it is increasingly difficult to carry out the manual guiding of cable in front of the take-up, because it is completely fenced in today. Even when it is possible to manually guide the cable onto the reel, the distance from the operator to the take-up may prevent a perfect winding. Pulleys To achieve the best possible control over the product, it is important to guide the product as close to the reel as possible. It is a key parameter to have as little distance from the pulleys guiding the product to the reel as possible.

The product is guided through a set of pulleys, which are dimensioned according to the diameter of the product. Because of the compact size of these pulleys, the distance to the reel can be minimised. Furthermore, the pulleys are shaped so that they are able to position the product very close to the flange. The guide arm is fitted with sensors detecting and measuring the distance to the flange, and these sensors ensure automatic change of traversing direction when the cable is next to the flange. The software controlling the precision winding unit is developed to optimise the quantity of product on the reel, eg by avoiding large gaps at the flanges when changing winding direction. During winding the guide arm turns 180 degrees so that the pulleys are always able to run very close to the flange. The flange detection system makes it superfluous to key in new parameters when changing to another reel size. The precision winding unit automatically adapts the traversing to the mounted reel and it is not necessary to change end-settings. When a layer is completed and the next one prepared, the guide arm moves up the ball rail by a distance equal to the product diameter in order to keep the product in its horizontal position. The inlet of the precision winding unit consists of a number of pulleys, which are mounted in a funnel position and thereby apply a minimum amount of pressure to the product, even though the line height changes as the reel becomes full. Using the precision winding unit makes it possible to fill the reel to the edge of the flanges. Reels It is important to position the product as close to the flanges as possible. Generally, it is recommended that flanges do not deviate more than half the product diameter. If, for example, a product has a diameter of Ø12mm, the flanges must not be more than 6mm off (±3mm). This means that the smaller the product diameter, the higher the demand for perfect reels. For a number of years Roblon has supplied take-ups with integrated precision winding units, capable of handling reels ranging from Ø380 to Ø1,400mm with a max gross weight of 1,800kg, and winding products ranging from Ø3 to Ø16mm.

Standard cables and similar products with a diameter of minimum 4mm can be wound with very high quality. Steel wires and steel tubes with even smaller diameters can also be wound using the precision winding unit. A prerequisite of a perfectly wound reel is that the reel itself is of high quality. The better the quality of the reel, the easier it is to achieve a satisfactory winding of the product. Safety Today it is sometimes necessary to manually guide the cable onto the reel and this process can be both time-consuming and dangerous. The person guiding the product will often have to focus exclusively on the winding process, and depending on the product he may have to stand immediately in front of the take-up.

▼ ▼ Guide arm

▼ ▼ Inlet pulleys

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September 2013