The patent claim reads:
This invention relates to improvements in low loss cables and has for a main object the provision of a cable formed of a plurality of conductors contacting each other at points and spaced apart from each other between said points, there being less surface area of conductors in contact at said points than the surfaces out of contact with each other between said points.
Another object of the invention is the provision of a conductor somewhat of the "Litz" type, comprised of a plurality of insulated conductors assembled into a cable with portions of their areas in contact and portions of their areas in non-contact relation with the other conductors, the areas of said non-contacting portions being far in excess of the areas of the portions in contact.
A further object of the invention is the provision of a cable formed of a plurality of conductors of sinusoidal form assembled to make point contacts with each other between the nodes of said sines, all other surfaces including said nodes being free to be contacted by surrounding air or any other medium.
A further object of the invention is the provision of a cable formed of four or more conductors each having a series of sinusoidal curves formed therein, said conductors touching each other at point contacts between nodal points of said curves thereby leaving a greater portion of said conductors free of contact with anything but the surrounding air.
Other objects will be apparent to those skilled in the art.
Here's an illustration:
The latest advanced audio cable geometry from the folks at Kimber? Well, if history repeats itself it might be.
Actually it's from patent number 2,218,085, filed in 1938 for a "low loss cable."
I happened across that patent because I was interested in another which cited this one as prior art.
A little over a year ago on another forum, I'd offered up some ideas with regard to making a Litz type cable using a four strand braid of wirewrap wire. During the course of that, I got to wondering if Kimber had ever patented their three-wire braid. They'd managed to get a patent on a series crossover (DiAural) so I was curious if the patent office had rubber-stamped a three wire braid.
So I went over to the patent office web site and did a search.
I didn't find any Kimber patent for a three wire braid, but instead I found that they'd recently been granted a patent on a four wire braid. I was rather taken aback (though not surprised given what the patent office has been granting these days). I'd used a four wire braid variously for years, the first time when I was 16 and cobbled together some impromtu speaker cables using some cloth covered 24 gauge telephone wire my grandfather had laying around. And I was sure I wasn't the first to have done such a thing.
Here's the illustration from Kimber's patent number 6,215,062:
Kimber hails this as their "
advanced GyroQuadratic™ field geometry."
I posted a little rant about this on the other forum in the course of which someone pointed out that Kimber's braid appeared to be identical to the braid used by Magnetic Shield Corporation in their Inter-8 cable which they've been selling for 45 years now.
I then realized that I'd seen that same braid dozens of times before over the years in MSC's pages in the EEM (Electronic Engineers Master catalog).
MSC says that the design is patented (though expired) but since the free patent databases don't let you search text prior to 1976 I didn't bother verifying it.
But I recently decided to make a commercial version of the four wire braided 30 gauge magnet wire I've been using and didn't want to get any grief from Kimber's lawyers so I called MSC and got the patent number (2,958,724 filed in 1958, a mere 41 years before Kimber
).
The 1938 patent is cited as prior art in the MSC patent so I thought I'd take a look at it and found it rather amusing that the opening claims of this 65 year old patent read as if it had been submitted in 2003 by some audio cable manufacturer.
Oh, almost forgot, here's the illutration of MSC's Inter-8 from their 1958 patent:
se
The more things change...
