"U.S. Trademark No. 2,894,980" by Knolls
"Miles Day Bed" by DWR.com
As discussed in the New York Times on October 28, 2004, Knoll's lawyers would have to convince a jury that there is a "likelihood of confusion" in the mind of the consumer before they could win a judgement for trademark infringement. When done faithfully knockoffs ensure that objects are available to a wider range of people and "spread awareness of good design. Consumers usually can't tell the difference unless they turn it over and look at the label," noted architect James Biber in the same article.
Just check for design patents before copying, Jim . . . .