If I am not mistaken, Dan Wessons used tranfer bars before Ruger, so maybe we should say that Rugers use "Dan Wesson style" transfer bars, although I think manufacturer who used it first was Iver Johnson in their "hammer the hammer" designs. By the time Dan Wesson or Ruger was using them, the patent had expired and was in the public domain.
Dan Wesson used many innovations in the late 1960's that many of the other manufacturers have since copied (i.e. Ruger's grip design on the GP-100 and many features on the new S&W X frames like the barrel and grip designs.)
Just a bit of useless trivia.
Roll Tide