This is the first Cyclo Gear Company derailleur patent to feature someone other than Albert Raimond or Louis Camillis. The new kid on the block is Arthur Everill, a man who sounds as if he may not have the best of sickness records. Perhaps Louis Camillis retired around this time.
The patent covers the method of adjusting the tension of the pulley cage by clicking the end of the spring into one of a number of shaped cutouts. The spring tension of the pulley cage was an obsession of derailleur designers well into the 1970s - and I am not entirely sure why. Perhaps spring steel was of poorer quality than it is today - or perhaps people expected their derailleurs to last longer. I can certainly remember resetting the spring tension of derailleurs - and I can remember Simplex models in particular loosing all tension - but today it hardly seems an issue.