The Sponge-Filter Inkstand: Press the Funnel and Clean Ink Rises Round the Pen

"Upon the top of said spring K, is fitted a plunger L, (made of cork or otherwise) and which can be moved up and down freely in said filter tube. The upper surface of said plunger is covered with a conical, or conical shaped cop M, firmly secured by cement, (or otherwise) upon the same. Said cop has a small opening N in its center (see Fig. 4, top view) precisely similar to the common funnel, with the tube removed, which is only large enough to admit the nib of the pen in using." "Concentric with said opening, is one of similar diameter through said plunger, in which is inserted a small piece of sponge as shown at O, which prevents a sudden jet of the ink when the pen is introduced, and also allows the ink to subside gently, when the pen is withdrawn, while at the same time it excludes the atmosphere from the ink in the filter-tube below."

**Top and tube.** Print a jar lid with a funnel-shaped ink tube through its middle and a filter tube, 12 mm inside, that screws onto the tube's lower end and reaches nearly to the jar's bottom. Close the filter tube's bottom with a cork drilled with a 1 mm hole, as Hunt's stopper H and aperture I. **Sponge, spring and plunger.** Push a plug of sponge into the tube's lower quarter, then a light compression spring. Cut a cork plunger that slides freely in the tube, drill it through, put a small piece of sponge in the hole, and cement a small printed cone on top with a hole just large enough for a nib. **Test.** Fill the jar with ink and fit the lid. Press a dip pen into the cone: ink rises round the nib. Lift the pen and write. Stir some fine dust into a second, open well of the same ink and compare the two pens' lines.

**Walter Hunt** of New York, New York, assignor to George Arrowsmith, received US 4,306, dated 11 December 1845. His metal top A had a flange B fitting the reservoir; the funnel-shaped ink tube C screwed into it with a collar E for the thumb and finger, and the filter tube G was fitted to it at a ferrule joint F; the spring K was to be of silver or another metal the ink does not affect. His claims are the filter tube with its funnel, plunger, spring, sponge and perforated bottom. **Honest limits.** A printed top and tube, corks and a bought spring stand in for his metal parts. The notebook assumes all the displaced ink goes into the funnel's mouth; its sizes and strokes are examples. Your lines are the result.