While one development in the shotgun world often leads to subsequent developments, patents don't work that way. Enough "tweaking" of something invented by someone else and voila! You have a new patent.
Argo, I'll quote to you from a letter I received from M. Claude Verney-Carron, president of the company, in 2002--responding to an article on French shotguns that I wrote for Shooting Sportsman:
"Helice was the name of the locking system patented by my great grandfather Jean Verney-Carron at the beginning of the 20th century. When the patent expired and fell in the public field a lot of gunmakers from St. Etienne adopted the system for their own use. That's why you can find a lot of brands derived from the word Helice. Verney-Carron used the following ones: Helice Grip, Helice 33, Helistop, Helicobloc, Heliduplex."
(I owned an Helice 33. Introduced in 1933--hence the 33--it was innovative in that it used coil rather than flat springs.)
