Sorry to come rather late to this thread but a new computer system got in the way of logging on!
Anyway, I am back now.
What has not been mentioned in this thread is the main significance of Needham's ejector patent.
We all see the ejector and assume that is the important bit. Not so.
As Gunman points out, although it was the first commercially successful, selective ejector system, it was swiftly superseded by several others: Baker, Perkes, Southgate, Deeley et al.
At that point, royalties on the patent should have dried up but David Baker mentions in his book that it did not and in fact the family were enjoyed the proceeds several generation on.
The part of the patent which was of real value was something which we assume was ubiquitous at the time but was not: the split extractor leg running in a single channel.
If you think about it, 99% of ejector systems use this design feature and Needham received the royalties for it for 14 years. Apparently, he sold the ejector system to Greener but kept the rights to the split extractor part. Clever man!
I am sure there are others, but the only well known ejector system that avoids this design feature is the Dickson which uses a separate leg for each extractor half.
