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The [[lever filler]] is probably the [[filling system]] most common among vintage pens (and has also been used, as a form of revival, by some modern manufacturers). Introduced massively to the market in 1912 by [[Sheaffer]], who has always proclaimed its invention, it has been produced in countless variations and versions, many of which, often technically inferior, have been created only to circumvent the patent ({{Cite patent|US|896861}}) that covered the invention of ''Walter Sheaffer'' that originated in 1908.

<noinclude>{{ReferBox|Filling systems}}</noinclude>The [[lever filler]] is probably the [[filling system]] most common among vintage pens (and has also been used, as a form of revival, by some modern manufacturers). Introduced massively to the market in 1912 by [[Sheaffer]], who has always proclaimed its invention, it has been produced in countless variations and versions, many of which, often technically inferior, have been created only to circumvent the patent ({{Cite patent|US|896861}}) that covered the invention of ''Walter Sheaffer'' that originated in 1908.

[[Image:LeverSchema.svg|center|500px|Diagram of a pen with ''lever filler'']]

[[Image:LeverSchema.svg|center|500px|Diagram of a pen with ''lever filler'']]

Other variations of the system concern the way in which the lever exerts pressure on the sac: for example the [[Eversharp]] did not use a flexible bar but a flat bar with the sides folded like a "U", anchored on a hook on the bottom of the pen. The lever was equipped on the external end with two tips that went to fit in the rail obtained from the folding of the bar, so as to raise it to the rest position after filling, furthermore to keep the lever locked in the rest position, it was equipped with small protrusions that went to fit into special recesses created in the housing slit.

Other variations of the system concern the way in which the lever exerts pressure on the sac: for example the [[Eversharp]] did not use a flexible bar but a flat bar with the sides folded like a "U", anchored on a hook on the bottom of the pen. The lever was equipped on the external end with two tips that went to fit in the rail obtained from the folding of the bar, so as to raise it to the rest position after filling, furthermore to keep the lever locked in the rest position, it was equipped with small protrusions that went to fit into special recesses created in the housing slit.

La [[Conklin]] con la [[Endura]] introdusse una versione del caricamento in cui soltanto la metà della levetta che veniva sollevata era esposta esternamente, riducendo le dimensioni della fessura di alloggiamento della stessa. Inoltre il meccanismo utilizzato dalla [[Conklin]], come quello della [[Eversharp]] non utilizzava una ''spring bar'', ma una barra di pressione era incastrata direttamente sulla levetta tramite due piccoli gancetti all'interno della stessa, che andavano ad incastrarsi in una apposito aggancio sulla barra.  

The [[Conklin]] with the [[Endura]] introduced a version in which only half of the lever being lifted was exposed externally, reducing the size of the slit on the barrel. Moreover, the mechanism used by [[Conklin]], like that one of [[Eversharp]], did not use a ''spring bar'', but a pressure bar was stuck directly to the lever by means of two small hooks inside it, which went to fit into a special hook on the bar.  

Una ulteriore variante degna di nota del sistema è quella della [[Carter]], derivata da un brevetto ({{Cite patent|US|1209978}}) della [[De Witt-La France]], che presenta una sorta di "guinzaglio" attaccato alla levetta che ne impedisce il ribaltamento una volta che questa ha raggiunto la posizione verticale, nell'ottica di evitare danneggiamenti alla penna ed al sistema.

Another noteworthy variant of the system is the one of [[Carter]], derived from a patent ({{Cite patent|US|1209978}}) of the [[De Witt-La France]], which has a sort of "leash" attached to the lever that prevents it from tipping over once it has reached the vertical position, in order to avoid damage to the pen and the system.

Infine una particolare versione di riempimento a levetta è quello della [[Skyline]] della [[Eversharp]], che potrebbe essere classificato anche fra i [[Caricamento#Caricamento a sfiatatoio|caricamenti a sfiatatoio]]. In tal caso infatti all'interno del serbatoio in gomma si ha uno sfiatatoio, e la ''[[spring bar]]'' è molto corta e volta a comprimere soltanto la parte finale del sacchetto. La penna viene caricata ripetendo più volte l'azione di pressione con la levetta, usando il principio classico dello sfiatatoio. Analogo a questo, anche se realizzato in maniera completamente diversa, è l'''[[Ink-Vue]]'' della [[Waterman]].<noinclude>

Finally, a particular version is the one of the [[Eversharp]] [[Skyline]], which could also be classified as a [[Filling systems#Breather_tube_fillers|breather tube filler]]. In this case, in fact, inside the rubber sac there is a breather tube, and the ''[[spring bar]]'' is very short and aimed at compressing only the final part of the bag. The pen is loaded by repeating the pressure action several times with the lever, using the classic principle of the breather tube filler. Similar to this, even if realized in a completely different way, is the  [[Waterman]] ''[[Ink-Vue]]''.<noinclude>

==Brevetti correlati==

==Related Patents==

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{{ListsPatentsFeature|lever filler}}

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