Pull lever( or the true lever ) with three main variations : without box ( the more commun) ,with box ( ex: LE Waterman's , Eclipse etc. ) and splitting lever ( ex: the Swan split lever or the Lotz lever we find in the Kraker pens: Pencraft, Monogram, Drew , Belmont and soon ). Besides these variations some manufacturers attached the lever in a reversed position oposite to the usual one like for instance the British Macauley or the American Eisenstadt .The invention of the lever filler it is attributed until today to Walter Sheaffer ( or at least the patent it is registered in its own name in the year of 1912 ) ;anyway we know today that this filler system was invented by a man called Barnes in the year of 1903 .The potential and eficacy of this filling mechanism was such that other pen makers followed very quikly with slightly different patents including the well known L E Waterman's pen maker and the less well known Eclipse Pen Co of New York who had introduced a self filler with a lever filler mechanism based on a patent registered in US by Marx Finstone the Eclipse' founder and owner ( anyway it is known through the articles writen bythe late John Roede,( Eclipse expert and collector)in some magazines that almost all the Eclipse patents registered in Marx Finstone name were in fact invented by his brother in law David Klein! ) . As a curiosity we can add that Eclipse patent for its lever was registered in August 28 , 1917 with No. 1,238657). Eclipse was founded in 1903 in S. Francisco by Marx Finstone with an export department in New York City by the mid twenties and with another factory in Toronto ( under the management of Joseph Tully ) and they supplied the Conway Stewart ( from UK ) lever filler mechanisms without bearing any identifying marks ( other than perhaps the US patent date inscribed in the lever ) from 1916 till 1920 ( until at least Conway Stewart could produce their own levers during late 1919/1920 ) .The lever filler is indeed one of the most widely used filling mechanisms and it is also very interesting for its simplicity and eficacy - as a matter of fact you only have to pull a small bar from the pen barrel wich is going to depress a rubber sac and when you release the lever bar and push it to the original position the rubber sac fills itself with ink with the vacuum created when it was depressed ! this lever was with time the place of a lot of modifications with the objective to " run out the patent infringe" but also to improve its eficacy and security ( we should remember the problems around the fixation of some levers to the barrel and its partial drop out from the barrel or even some broken barrels due to much pression from the lever! ) .If technically the evolution of the the lever filler it is very interesting ( and in our opinion one of the more important adition was the lever box ) , we can not forget the otherfunctions of the levers : decorativo , or as one more place in the pen to imprint anything like the brand name or just a letter related with the brand name ( S for Supremacy or Spencerian , E for Eisenstadt and so on ) or even the patent number ( like in some All American Conklin models ) !And when we put toghether function with beauty we have what ? You right : we have Design ! And we can talk without favour not only about design of a pen but also about design of a so small pen device like the lever filler ! So what did begin as an important part of a pen besides keeping its function did adquire another important function : decorative !We can easily remember for instance the nice engraved lever of the diferent Waterman's models from the " VINE " sterling overlays .And we see levers with diferent forms : completely straight , with diferent ends ( circular, elliptical , triangular or with other geometrical forms ) imprinted with the brand names or models and so on. But the top of this beautiful levers was reached during the Art Deco period in particular with the more important French manufacturers !After this introduction about this filling system enjoy these woderful Sheaffer's pens .