Fixing a Distorted coiled Handset Cord, Improved method

[Stormcrash]

The patents may be for the apparatus doing the initial coiling alone rather than for the entire manufacturing process, assuming a reversal step done either manually or by another machine once the cord is off the rod. In the how it's made video they're pretty coy but the suspicion is that it's just done with that drill exactly like they show.

Also as an FYI the earliest color 500 sets from the 50s actually have a fatter coil cord than sets. The change to the thinner cords happened before the end of soft plastic production. A lot of those "fat" cords seem to have a spiral in the opposite direction as well from what later seemed to be standard

[TelePlay]

I agree and unless we find someone who worked at WE making the cords, we will never know. The patent documents are long, confusing and leave out a lot of information including the chemistry of the cords, cord dimension and steps in the process that could not be patented.

There are so many different types, sizes, colors and materials used to make cords there really can't be a one size fits all coiling process.

Starting with the same material (chemistry, and use modern thermoplastic) to be coiled, machine feeding cordage right out of the extruder (where it was just formed and it's still molten hot just beginning to cool) onto a mandrel is different than wrapping a strait l, cold cord around a mandrel and heating it.

The characteristics of the coils would be different.

The hot cord would be tighter wrapped on the mandrel and more or less formed at time of creation into a coil.

The cold straight cord would not be flexible as a hot, just formed cord and as such the cold winding on the mandrel would not be as tight as the hot wrapped cord. Cold cord wrapping and then heating would not create a tight coil and would be helped by reversing the coil.

When I wrap already coiled cords on an aluminum rod, it's hard to get them tight and have to go over the wrapped cord 3 or 4 times to get it tight on the rod with the coils touching before heating. I can imagine how hard it is to coil a straight cord onto a rod to get it tight. And being round would mean the cord as it flattens with heating against the rod would slightly loosen the coils on the rod, put slack into them and produce a coil that is not as tight as the "hot" coiled cordage. A machine loaded hot cordage on a rod would better form the coil.

I've restored over 50 coiled cords and found that to be the case every time. Once I tried to coil a straight XLR sound cable using the wrap and heat process. The resulting coil was not tight (and did not know to try to reverse the coils - if I can find a length of junk XLR cable, I could try that again with reversing the coil).

The chemistry of cordage materials and their colors is as complex as that of injection molding different types of colored plastics. And 50 to 70 years after original production, all we get to see is the end product needing help 50-70 years after it was made and trying to figure out a solution by analysis, trial and error.

All I know from experience is that newer (thermoplastic?) cords and their inner conductors have a much longer usage life span than older (fat and black rubber?) cords, some of which I have are no longer flexible, break apart when flexed and the inner conductor coverings crumble with any movement.

[TelePlay]

I have some old, used XLR cable somewhere in a box in my basement. When I find it, I'll try an experiment. Could use straight, round line cord if I find any first.

1) wrap a length around a 3/8" rod, heat it to 200F and let it cool.

2) use an equal length, heat it to 200 F before/as I wrap it onto a cold rod and let it cool.

3) compare the "tightness" of each coil

4) if the "cold" wrapped coil is not as tight as the "hot" wrapped coil, reverse the coil and re-compare the "tightness" of each coil.

Everything will be kept the same except for the coiling process, using a true scientific method of changing only one variable in a duplicated experiment.