From 1991, these Sony reference the ad which is odd since the ad is several years before the patent. https://patents.google.com/patent/USD328074S/en
Here's a neat one from 1981, while similar to the Walkman II this has a built in radio. https://patents.google.com/patent/USD275391S/en
With little modifications, this became the DD9. The same inventor apparently designed the WM-B603 / WM-EX49C: https://patentimages.storage.googleapis.com/51/cd/84/cf51e7bfb70088/USD316095.pdf
I'll click the inventor links or the "similar art" and sometimes you can find some other nuggets, also the links to other designs that reference the patent your looking at. The biggest thing I get is that most of these guys were really intelligent engineers with a ton of advanced electronics patents and two or three "portable cassette player" design patents under their belts. I wonder if the design patents were a nugget the boss threw at them for all of the other work, for most products like these a dedicated industrial design company would be used. It looks like the Philips Roller Boomboxes I posted above did use a USA Designer. Post anything you find, there's a lot of it. If anybody else is looking at these, check out the links, there's usually many more drawings, I like to post the isometric drawings (45 degree). I do love these drawings, I went to school when we still used mechanical drafting tables (Vemco) and had a handful of different pencil thickness's and color shades. We did shift over to AutoCad and CadKey but we had to program our own 3-D CAD programs, I think in C+? The powerful ones were only available to big companies and dedicated computers (SUN) back then.
