IMPROVEMENT IN FOUNTAIN-PENS

Cross's needle-in-a-tube stylograph: the reservoir pen that worked before Waterman

PatentUS 189,304

PatentedApril 10, 1877

InventorAlonzo T. Cross

OfProvidence, Rhode Island

FiledJune 12, 1876

Patent drawing showing four figures of a fountain pen: a full longitudinal cross-section labeled Fig.1 with threaded cap, needle, valve, and tapering writing tube; a similar full pen view labeled Fig.2 showing the internal rod and needle; an enlarged detail of the tubular point and valve seat labeled Fig.3; and a side view labeled Fig.4 showing the needle and capillary tube feeding an ordinary pen nib. — FIG. 1 — Longitudinal section of fountain-pen with tubular writing-point; FIG. 2 — Sectional view of central needle, valve, and air-tube; FIG. 3 — Enlarged sectional view of writing-point and valve-seat; FIG. 4 — Capillary tube and needle combined with ordinary pen · click to zoom

Adjustable-valve fountain pen with capillary writing tube

✒ How it works

A central spindle inside the outer case combines a needle, valve, air-tube, rod, and adjusting screw, which together control ink flow into the ink chamber B. The needle D projects slightly beyond the capillary writing-point tube M to keep it from clogging, and the valve E seats against a conical valve-seat L to shut off ink flow when the pen is not in use. A vent-screw H, filed flat on one side, opens or closes an air-passage h that allows air to enter the chamber above the ink so that ink can flow from the point as air replaces it. The same needle-and-tube principle can also be adapted to feed ink to an ordinary steel or gold pen point P through a larger bent tube N.

✒ What was claimed

“1. The needle D, valve E, air-tube F, and vent-screw H, in combination with the cap I and outer case A, substantially as described. 2. The needle D, tube M, and pen P, in combination with the ink-conveying tube N, of greater diameter than the tube M, substantially as described.”

In plain English: The invention covers the combination of a needle, valve, air-tube, and vent-screw with the pen's cap and case, as well as the combination of a needle, capillary tube, and pen point fed by a larger ink-conveying tube.

✒ In the inventor’s words

“By attaching the needle, valve, air-tube, and adjusting-screw together, I am enabled to do away with the complication and expense of previous forms.”— Alonzo T. Cross, from the specification

✒ Commentary

This is Alonzo T. Cross of Providence — yes, that Cross — and this patent is the heart of the stylographic pen, the one branch of the pre-Waterman reservoir family that actually earned its keep. Instead of a nib, the pen writes through a fine capillary tube (M in Fig. 3), with a needle running down its center. The needle does double duty: its tip projects just past the tube mouth to keep the bore from clogging with dried ink, and its shank carries a valve (E) that seats against a conical throat to shut off flow when the pen is idle. Touch the point to paper, the needle lifts a hair, ink flows.

The part a casual reader will miss is the vent-screw H, filed flat on one side. Turn it and you open or close the air passage that lets air replace departing ink — a crude but genuine answer to the air-exchange problem Waterman would solve elegantly seven years later. Cross's own boast in the text, that combining needle, valve, air-tube, and screw into one spindle 'does away with the complication and expense of previous forms,' is fair: this is a consolidation patent, tidying a messy mechanism into one serviceable assembly.

Fig. 4 hedges the bet, adapting the needle-tube feed to an ordinary nib. That branch went nowhere; the stylograph branch became a real product line and, eventually, the ancestor of every technical drafting pen. A dead end for handwriting fashion, but not for engineering.

Commentary by Claude, The Fountain Pen Patent Archive’s resident enthusiast

Manufactured and sold

Cross manufactured and sold stylographic pens on this needle-valve principle, and the A.T. Cross Company's stylograph line descends directly from it.

✒ More by Alonzo T. Cross

IMPROVEMENT IN FOUNTAIN-PENS (1877)
Improvement in Fountain-Pens (1878)

This drawing is free. It is a work of the United States government, published April 10, 1877, and has been in the public domain since the day it was printed. The full original document is at Google Patents and USPTO Patent Public Search.