M Modern rope-making ingenuity reaches its high-water mark in the compound laying-machine where the two operations of forming the strands and laying them into a rope are combined. Up to a certain point this method is more economical than that in which the forming and laying are unconnected as already described. Fewer machines are required for a given output,—hence less floor space and fewer workmen. The time-saving element also enters in.
The compound laying-machine must, however, be stopped each time that the supply of yarn on any bobbin is so low as to call for a fresh one. This would occur so frequently in the case of the larger ropes as to offset the advantages just mentioned, and the machine is therefore used on a limited range of sizes only.
As can be seen in the picture opposite, the machine contains a vertical shaft with upper and lower projecting arms which support the bobbin-flyers—four in number in this particular case. The bobbins within each flyer turn on separate spindles, allowing the yarns to pass up through small guide plates and thence into a tube.
Each flyer is geared to revolve on its own axis, thus twisting its set of yarns into a compact strand. At the same time all the flyers revolve with the main shaft in an opposite direction and form a rope out of the strands as the latter come together in a central tube still higher up.
The rope is drawn through this tube by a series of pulleys which exert a steady pull and so keep the proper twist in the rope. From these pulleys the finished product is delivered onto a separately driven coiling reel, an automatic device registering meanwhile on a dial the number of feet run.
The small reel, seen near the head of the main shaft, holds the small heart rope which is fed into the center of certain four-strand ropes to act as a bed for the strands.
The compound laying-machine can be had in many sizes of differing bobbin capacity, and the extent and variety of a manufacturer’s equipment on this type is one important indication of his ability to turn out promptly and at a reasonable price the sizes of rope in most common demand.