US 260134 Jun 27, 1882, the Stone patent purchased by Wirt in 1887. CITED ON TWO LINE IMPRINT WIRT PENS. Feeds shown here
US 266247 Oct 17, 1882, closeable air vent at feed
US 288290 Nov 13, 1883, early split feed
US 311554 Feb 3, 1885, two piece feed. CITED ON SINGLE LINE IMPRINT WIRT PENS. Feeds shown here
UA 328169 Oct 13, 1885, overfeed with odd support
US 330358 Nov 10, 1885, one piece overfeed
US 358525 Mar 1, 1887, nib overlay (possibly used by Crown pens?)
US 370438 Sept 27, 1887, pencil
US 399306 Mar 12, 1889, folded nib/nib overlay
US 526425 Sept 25, 1894, retractable nib pen with end knob
US 526426 Sept 25, 1894, retractable nib “type 1”. See example
US 526427 Set 25, 1894, retractable nib “type 2”. See example
US 526428 Sept 25, 1894, safety screw cap. Used on ruling pen and safety cap pens.
US 544712 Aug 20, 1895, pencil 2
US 651735 Jun 12, 1900, underfeed
US 651736 Jun 12, 1900, double reservoir pen
US 651737 Jun 12, 1900, another double reservoir pen
US 651738 Jun 12, 1900, double reservoir pen AS PRODUCED. See example
US 675698 Jun 4, 1901, ink shut off
US 675699 Jun 4, 1901, another ink shut off
US 706140 Aug 5, 1902, tubular underfeed
US 706141 Aug 5, 1902, over and underfeed, as produced, but patent not listed on the pens themselves. Feed shown here
US 723112 Mar 17, 1903, over and underfeed
US 723113 Mar 17, 1903, another feed
US 724983 Apr 7, 1903, vented underfeed.
US 724984 Apr 7, 1903, vented underfeed as produced. CITED ON UNDERFEED PENS. Feed shown here
US 764652 Jul 12, 1904, folding rod syringe filler
US 841475 Jan 15, 1907, piston with detachable rod. See example
US 852368 Apr 30, 1907, hump filler. (Looks like the Betzler hump filler)
US 852369 Apr 30, 1907, hump filler as produced, but not imprinted on the hump filling pens. See example
US 978419 Dec 13,1910, ink shut off as produced, but not imprinted on the safety pens. See example
US 978420 Dec 13, 1910, underfeed seen since 1903, but patent date is 1910! See feeds here
US 1347800 Jul 27, 1920, lever filler and floating pressure bar as produced. See example
US 1379890 May 31, 1921, lever and spring mounted pressure bar as produced. Restoration example. Pen examples.