Cap

Versione del 16 dic 2018 alle 15:49 di Piccardi (discussione | contributi) (Creata pagina con "Historically, the first caps were made with a friction closure (those that are generically defined ''slip caps''), with the cap that fits on the body. There are different...")
A particularly elaborated cap

Apart from some particular designs (the Pullman of Météore, the Asterope of Aurora and the Capless of Pilot) the cap remains one of the essential components of a fountain pen. The cap basically performs two functions, on the one hand it provides the protection of the nib against accidental bumps to the outside, on the other hand it protects the outside from accidental contact with the nib (and especially with the ink brought by the same) and from any leaks.

From a technical point of view, many inventions have been applied to the cap, almost always related to the way in which it can be opened or closed (interlocking, screw, snap, now also magnetic) and sometimes also to the way in which it can be inserted on the bottom of the pen to balance the weight or size of the same, as in the case of the Pilot Elite (but there are many precursors) in which for the use of the pen it was necessary to put the cap on it because this was a necessary extension of the body.

A second role played by the cap is to keep the environment around the nib well circumscribed, with the pen closed, so that the ink present on it does not dry out (causing a difficulty in restarting) on the one hand but does not even undergo pressure changes that can cause ink to escape. For this reason, there are both ventilated caps (with the presence of ventilation holes) and caps that are completely sealed. In particular, at the beginning of the 1900s, in order to guarantee against the loss of ink, the presence of a second inner cap began to be introduced as a constitutive part of many caps (significant patents nº US-764227 and nº US-1028382), which encloses the part on which the section is bent and isolates it from the rest of the cap, guaranteeing the seal of the ink. Sometimes this same element is also used as a locking component in the assembly of the clip, which can be mounted in a ring on the same, or wedged between the cap and inner cap by means of a lateral slot.

The cap is also often a characteristic element for the design and lines of a pen, and can be the subject of various decorations. Among these, a common element, widely used and still present on most of the caps, are the bands, or the various rings, whose original purpose was also strictly practical in nature. The edge of the cap is in fact one of the most stressed and subject to the risk of breaking a pen, and the original use of rings and metal bands (see patent nº US-662796) was precisely to reinforce the edge, and only later these have assumed the character of a decorative element.

Historically, the first caps were made with a friction closure (those that are generically defined slip caps), with the cap that fits on the body. There are different variants of this type of choice, depending on the way in which the joint is made; the two main classes are the so-called cone cap (conical section cap) in which the interlocking surface is a truncated cone, and the so-called straight cap (cylindrical section cap) in which the interlocking surface is cylindrical, among the latter there are then the so-called tapered cap (conical or tapered cap) in vogue at the end of the 19th century.

Ai cappucci ad incastro, che soffrono, specie nella versione conica, di problemi di usura delle superfici con perdita di tenuta, sono seguiti, con una tendenza affermatasi a partire dagli inizi del '900, i cappucci con chiusura a vite (threaded cap) che ancora oggi sono fra i più diffusi. Un ritorno dei cappucci ad incastro si è avuto negli anni '40 con l'introduzione dei cappucci in metallo chiusi a frizione su appositi anellini (tendenza introdotta dalla Parker 51).

Verso la fine degli anni '40 è infine iniziata la diffusione dei primi cappucci con chiusura a scatto (una delle prime aziende ad averli utilizzati è stata la Matador con il modello Matador-Click del 1949) divenuti in seguito molto comuni e tutt'ora in ampia diffusione. In questo caso la qualità del meccanismo è essenziale per garantire nel lungo termine il mantenimento della chiusura del cappuccio.

Brevetti correlati

  • Brevetto n° US-614630, del 1898-11-22, richiesto il 1898-01-28, di William W. Stewart, Swan. Chiusura cappuccio.
  • Brevetto n° US-711988, del 1902-10-28, richiesto il 1902-05-18, di George W. Mabie, Swan. Fondello per cappuccio.
  • Brevetto n° FR-395110, del 1909-02-11, richiesto il 1908-10-09, di Paul E. Wirt, Wirt. Cappuccio di sicurezza.
  • Brevetto n° US-950939, del 1910-03-01, richiesto il 1908-06-04, di Clarence E. Martling, Charles Dunn, Dunn. Cappuccio a tenuta.
  • Brevetto n° US-978419, del 1910-12-13, richiesto il 1908-10-31, di Paul E. Wirt, Wirt. Cappuccio di sicurezza.
  • Brevetto n° DE-813669, del 1951-09-17, richiesto il 1948-10-02, Uhu. Cappuccio fondello.