Modifiche

<noinclude>{{ReferBox|Filling systems}}</noinclude>The loading system called ''Touch Down'' by the company itself was introduced by [[Sheaffer]] in 1949 for the [[Touchdown|homonymous models]], and is nothing more than a more sophisticated reworking, carried out after twenty-five years (patent {{Cite patent|US|2610612}}), of the [[Chilton]] [[pneumatic filler]] system (whose patent, {{Cite patent|US|1528379}}, is mentioned explicitly). In fact, the operating principle is essentially identical, what changes is the way in which the pneumatic compression of the rubber sac inside the pen is carried out.

<noinclude>{{ReferBox|Filling systems}}</noinclude>The loading system called ''Touch Down'' by the company itself was introduced by [[Sheaffer]] in [[1949]] for the [[Touchdown|homonymous models]], and is nothing more than a more sophisticated reworking, carried out after twenty-five years (patent {{Cite patent|US|2610612}}), of the [[Chilton]] [[pneumatic filler]] system (whose patent, {{Cite patent|US|1528379}}, is mentioned explicitly). In fact, the operating principle is essentially identical, what changes is the way in which the pneumatic compression of the rubber sac inside the pen is carried out.