− | A more efficient system, later used by other producers, requires the lever to be held in place by a metal ring through it (patent {{Cite patent|US|1292736}}). This is inserted inside the pen and maintained in position by means of a special groove, made internally on the barrel in correspondence with the lateral opening from which the lever itself is housed. This system has the considerable advantage of greater mechanical strength, since it does not require drilling holes for the pin in the material of the barrel, which in ebonite pens was often quite fragile. | + | A more efficient system, later used by other producers (including [[Sheaffer]], but only after patent expiry), requires the lever to be held in place by a metal ring through it (patent {{Cite patent|US|1292736}}). This is inserted inside the pen and maintained in position by means of a special groove, made internally on the barrel in correspondence with the lateral opening from which the lever itself is housed. This system has the considerable advantage of greater mechanical strength, since it does not require drilling holes for the pin in the material of the barrel, which in ebonite pens was often quite fragile. |