Re Japanese vacuum clones: I am not quite sure how strong the copyright laws are in Japan, but having lived in Tokyo for a short while in summer of 1988, I can attest to the fact that the assortment of canister vacuums available in stores looked very very uniform across all the brands: National Panasonic, Sanyo, Hitachi, Toshiba, Mitsubishi, etc. For example, it looked like all the companies got their electrified hoses from one supplier - all the hose handles had similar power switches. The bagless vacs all had similar “dust cassette boxes” that used large filter boxes with combinations of fine mesh screens and accordion fabric filters. Even the carpet/bare floor nozzles looked very similar…probably coming from one supplier - similar to how Wessel Werk supplies so many similar carpet nozzles to a wide array of manufacturers.
It would be interesting to find out how one particular innovation was not protected by any copyright: on many Japanese canisters pulling out and rewinding the cord also caused a gear mechanism to “flick” the panels of the fabric filter to release fine dust into the cassette box!